Inquiry chairman Sir Wyn Williams says two expert witnesses have been appointed to deal with "governance issues".

They are Dame Sandra Dawson and Dr Katy Steward and have been instructed to produce two reports addressing issues relating to leadership, management and governance.

Dame Sandra is professor emerita of management studies at University of Cambridge. Dr Steward has spent 20 years in the NHS.

Post Office investigator Stephen Bradshaw is up now.

Dressed all in black, he's being sworn in.

Stay with us as we bring you what he says.

Sam Hancock
Live reporter at the Post Office inquiry

I'm in a very busy - but not packed - inquiry room, where Stephen Bradshaw, a former Post Office investigator, is about to be sworn in to give evidence.

There's more on him in one of our earlier posts, which you can read here.

He's looking on as Sir Wyn Williams, the chair, takes his seat and gives those of us here some housekeeping rules for the day. He's mainly talking about when the next phases of the inquiry will begin - we're currently in the fourth. There's five, six and seven to go.

Williams jokes that there was a news report published yesterday, suggesting phase six wouldn't begin until spring next year - something he says his wife gave him grief over.

I've just spoken to a journalist who's been covering this scandal for years - he says today's noticeably busier than it has been in the past.

The Post Office inquiry is just about to get started.

We're expecting to hear first from Stephen Bradshaw, a Post Office investigator involved in the criminal investigation of nine sub-postmasters.

You can watch all the latest from Aldwych House by pressing Play at the top of the page.

Sam Hancock
Live reporter

Good morning from Aldwych House, in central London, where today there's an order of business that everyone's talking about - the Post Office Horizon IT inquiry.

It's not the beginning of the inquiry (which started in 2021) and it's in no way a reaction to the last few days - though you'd be forgiven for thinking it was.

Rather this is the continuation of an inquiry that's been under way for years, but it's safe to say it's fourth phase restarts with a whole new wave of interest following the events of this week.

Some former sub-postmasters and postmistresses have begun arriving - some have made a point of telling those of us wearing press passes about the impact the recent ITV drama, Mr Bates vs the Post Office, has had.

I'm inside the room where today's hearing is taking place - stay with me and the team back in the newsroom as the day unfolds.

As we've been reporting, the inquiry is set to hear from Stephen Bradshaw, a former Post Office investigator.

Prior to the Post Office Horizon scandal hitting the headlines again in recent days, Stephen Bradshaw might have thought his evidence at the inquiry would have been heard by a handful of reporters.

The reality will be very different today, with dozens of journalists and countless media following the first hearing of the year.

Bradshaw has been described in previous hearings as having a “heavy footprint” in the Horizon IT scandal by lead counsel Jason Beer KC.

He was involved in the investigation of nine sub-postmasters and sub-postmistresses, including Lisa Brennan, who was falsely accused of stealing £3,000 in 2003 at a post office in Huyton, near Liverpool.

Bradshaw has also been accused by Rita Threlfall, another sub-postmistress, of asking her for the colour of her eyes and what jewellery she wore before saying “good, so we’ve got a description of you for when they come”, during her interview under caution in August 2010.

A former Post Office investigator - whose work led to criminal proceedings against sub-postmasters - is up shortly to face questions at the public inquiry into the Horizon IT scandal.

The hearings began in February 2022 - but these latest evidence sessions are set against a backdrop of increased scrutiny about the miscarriage of justice, following the broadcast of an ITV drama on the subject.

Here's a bit more about the inquiry:

• Who's in charge? Its chairman is Sir Wyn Williams, a former High Court judge who rose to become the senior presiding judge for Wales. Since his retirement he has been mostly involved in mediating sports-related disputes - until he took on the Post Office inquiry
• What's been covered so far? The inquiry has already heard on how the scandal has impacted victims; looked at the design and roll-out of the Horizon IT system and considered how disputes were resolved and how errors in the system were fixed
• Where are we at now? Phase four. This is all about the action taken against sub-postmasters and sub-postmistresses and includes looking at policy making, the court cases and, perhaps crucially, the knowledge of and responsibility for failures in the Post Office's investigations
• How long will it take? It's expected the inquiry will be finished by this summer at the latest

Pauline Stonehouse, a former postmistress, says the intense media scrutiny of the Post Office prosecutions has left her feeling like Edvard Munch's painting The Scream.

Speaking on BBC Breakfast, she describes putting her hands to her face this week and wanting to scream because "the world's gone mad with the coverage of this scandal."

She ran a PO branch in Seaburn, Sunderland and in 2008 was one of more than 700 managers found guilty of false accounting, theft and fraud based on figures from faulty software.

Her conviction was overturned in 2022.

Stonehouse says the response to the ITV drama is overwhelming and brings back a lot of bad memories of the time when it happened, including interrogation by the investigators.

She ended up losing her business, declaring bankruptcy and had to be rehomed by the council with her young children.

In addition, Stonehouse says having to ask her husband if he had stolen the money was one of the worst experiences, stating it could have ended her marriage.

She says she'll never forgive the Post Office for that.

Read more about Pauline Stonehouse's story here.

Jason Coyne, an IT expert, was instructed to examine the Horizon computer system by the Post Office in 2003.

He says he notified the Post Office the data was "unreliable" but he was ignored, sacked, and then discredited.

Speaking to BBC Breakfast he says: "What was always obvious to me was that the Post Office had adopted a position that there were no bugs in the Horizon system.

"Even before looking at it, I knew that couldn't be the case because every computer system has bugs. It's just how you deal with the impact of those bugs and how you investigate what happens."

In 2016, he was approached by Alan Bates, who was one of the main claimants who brought a case against the Post Office and went on to inspire the ITV drama.

Coyne was instructed as an expert witness but says trying to get answers from the Post Office was like "pulling teeth".

But, he says, he feels more optimistic about the case now with all the press and government attention it's getting.

Read more about Jason Coyne's story here.

James Hartley is a partner at the law firm Freeths, which fought in the High Court for the 555 ex-sub-postmasters whose group court case helped to expose the injustice.

Hartley welcomes the government’s announcement yesterday, telling BBC 5 Live that it “feels like a very positive step forward”.

The blanket overturn of the convictions, he says, is the “right thing for the government to have done”, adding that the risk is “minimal”.

He adds that his firm will continue to gather evidence of what the postmasters experienced during the scandal, such as medical reports detailing psychological damage.

He encourages everyone affected to come forward, saying they no longer need to be afraid of being intimidated.

“They should not hesitate now, because it’s safe.”

As a reminder, the 555 claimants won £43m compensation from the Post Office in 2019 - although most of the money was swallowed up by a "no win, no fee" agreement with Therium, the company which funded the litigation. Of the 555, only 62 had been criminally convicted., external

Image source, EPA

Sub-postmasters and sub-postmistresses are managers at Post Offices across Britain. They take responsibility for the everyday running of a Post Office, including the money going in and out of the business.

They handle people’s savings and pensions, and are often at the heart of their communities.

Between 1999 and 2015, the Post Office prosecuted 700 sub-postmasters and sub-postmistresses - an average of one a week - based on information from a faulty computer system called Horizon. Some 283 other cases were brought by bodies including the Crown Prosecution Service.

Postmasters and postmistresses were jailed, went bankrupt, saw their marriages destroyed, and some died before their names were cleared.

Image source, PA Media

James Arbuthnot is a former MP who now sits in the House of Lords and has campaigned on behalf of sub-postmasters for several years. He also sits on the Horizon Compensation Advisory Board.

He says he has faith in the ongoing public inquiry, saying “I think we are getting to the right solution but it has taken far too long”.

Arbuthnot says he did not think the culture inside the Post Office - which, the inquiry has heard, saw investigators incentivised with bonuses to claw back money from sub-postmasters - has changed.

He continues: ”Those investigators weren’t investigating, they were just trying to uncover money.

“When people called in investigators for help because Horizon was going so badly wrong, they got no help. They were just asked ‘where is the money?’.”

But he says the Post Office has been “chastened and is becoming as ashamed as they really should be”.

The public inquiry is due to hear from a witness who worked as a Post Office investigator later this morning.

The prime minister says the government will bring in a new law to clear the names of all the sub-postmasters and mistresses in England and Wales who were wrongfully convicted because of a faulty computer system.

According to the Department for Business and Trade there have been 983 UK-wide convictions, with 700 being Post Office prosecutions and 283 prosecutions brought by other groups, including the Crown Prosecution Service, since the Horizon System was installed in 1999.

So far just 95 have had their convictions overturned.

The Post Office prosecutions include some in Scotland and Northern Ireland, where separate action will have to be taken to clear those affected.

Scotland’s First Minister Humza Yousaf said he was also keen to work with UK ministers on the issue.

Hash Shingadia runs a shop in Bucklebury, Berkshire - it was used by the Princess of Wales when she was growing up, and he was invited to her wedding to Prince William.

Shingadia's shop used to have a Post Office branch - and just months after the royal wedding in 2011, he was wrongly convicted of false accounting.

He was given a suspended jail sentence, and 200 hours community service, because of the faulty Horizon software.

"It was hard, really really hard," he tells BBC Breakfast. "At times I had suicidal thoughts."

His conviction was overturned in 2021, and Shingadia welcomes yesterday's news that hundreds of others will also now be cleared.

"At last they'll be able to hold their heads high," he says.

Image source, Hash Shingadia

The public inquiry into the Post Office scandal is set to resume at 10:00 GMT today.

Its aim is to clearly understand the failings of the Horizon IT system – for which hundreds of people were wrongfully punished.

The inquiry first began in February 2021. Phase four of the inqury is expected to probe into the action taken against sub-postmasters and sub-postmistresses.

Today the inquiry will hear from Stephen Bradshaw, a former Post Office investigator.

Bradshaw was involved in the criminal investigation of nine sub-postmasters, interviewing them as part of the investigation into fraud.

Our reporter Sam Hancock is at the inquiry this morning, bringing us live updates once the inquiry gets going. We’ll also have clips, reaction and analysis right here, so stay with us.

Image source, ITV

The director of the ITV drama Mr Bates Vs The Post Office, James Strong, says the impact of the show is "beyond all of our wildest dreams".

Speaking to BBC Radio Bristol, he says he had hoped the show would shed some light on the issue and inform a million people. Instead, it has "grasp[ed] the whole nation".

He says the showrunners were successful in making people care about what the postmasters and postmistresses went through.

Strong adds that it is right that the issue is getting the attention it deserves, calling what people went through an "absolute scandal".

Woking MP Jonathan Lord first called for an inquiry into Post Office prosecutions in 2011.

Speaking to the BBC, Lord says if more had been done then, "a lot of heartache, and lives, and money could have been saved”.

“There’s no doubt that the Post Office and Fujitsu indulged in a cover up on a massive scale.”

Lord says that backbenchers came forward on behalf of constituents and that they encouraged the Post Office to get forensic accountants.

“As soon as those accountants started to find out things to worry the Post Office they terminated their contracts immediately and didn’t allow them to speak outside of the Post Office.”

To hear more from Lord’s interview on BBC Radio Surrey click here.

Professor Chris Hodges is chair of the Horizon Compensation Advisory Board, an independent group tasked with overseeing payments related to the Post Office scandal.

He tells BBC Radio 4’s Today programme he is “delighted” by the move to overturn convictions, but says it should be turned into law in the next few months rather than by the end of the year.

Prof Hodges broadly welcomes the government's new offer of £75,000 to hundreds of sub-postmasters who were not convicted of a criminal offence but used their own savings to plug losses.

He says the amount of compensation being discussed in individual cases ranges from £10,000 to well over a million, and the offer of a quick £75,000 settlement might suit people who don’t want to spend time reliving their suffering by going through a full financial assessment process.

Image source, EPA

We've been hearing about the unexplained shortfalls sub-postmasters and mistresses were experiencing - but what actually went wrong with the Horizon IT system?

It's the responsibility of those running Post Office branches to balance their accounts, which had previously been done on paper, but in 1999, Fujitsu's Horizon was introduced.

Almost immediately there was an increase in the number of staff experiencing accounting shortfalls which they could not explain.

Josephine Hamilton, a former sub-postmistress from South Warnborough, who was convicted of fraud, says she saw the amount "double before her eyes" while using the software.

Josephine said at first the Horizon system showed there was £2,000 missing.

She then contacted the Post Office support, who advised her, but after following their instructions, the amount doubled to £4,000.

Many reported that the Horizon system made it look like money was missing when it wasn't.

Jason Coyne, an IT expert, was instructed to examine the computer system in 2003 and reported "concerning discrepancies".

Coyne said there "was clearly defective elements of its hardware, software and interfaces, and the majority of errors noticed in the fault logs could not be attributed to the sub-postmaster".

Coyne said the Post Office data was "unreliable" but he was ignored, sacked, and then discredited.

The lawyer for a sub-postmistress who was wrongly jailed while she was pregnant said what made her most angry was the basis of the British justice system - innocent until proven guilty - had been turned on its head.

Seema Misra was pregnant with her second child when she was convicted of theft and sent to jail in 2010.

Speaking to the BBC, Flora Page said Seema’s life was “finally getting into shape” but it had been a “terrible injustice”.

“She was pregnant when she was put into prison, her son’s whole life has been about Seema’s fight for justice," she added.

Page explained that it was complicated to get your conviction overturned and that she had become involved when the Court of Appeal received Seema’s referral.

She added that Seema has had some interim payouts but the compensation "was not settled”.

You can hear more from BBC Radio Surrey’s interview with Page here.