We're leaving our live politics coverage there for now - but you can read our main story here, and catch up with our explainer on the tax affairs of Conservative Party chairman Nadhim Zahawi here.

Today's page was written by Thomas Mackintosh, Gem O'Reilly, James Harness, Chas Geiger and Richard Morris. It was edited by Marita Moloney and James FitzGerald.

Image source, House of Commons

It was a surprise to many that Labour leader Sir Keir Starmer didn't focus all his questions to Prime Minister Rishi Sunak on the matter of the tax affairs of Nadhim Zahawi - given all the recent pressure on the Conservative party chairman.

• Instead, Starmer chose to highlight failings within the probation service - revealed in a recent report - that led to a man with a history of violence murdering trainee lawyer Zara Aleena. The Labour leader said ministers were responsible for many of the systemic problems identified
• Rishi Sunak said "this was a truly terrible crime" and the failures highlighted were "unacceptable". He blamed failings in the initial risk assessment, and said steps were being taken to address issues raised
• Turning to Zahawi's taxes, Starmer suggested the job of prime minister was "too big" for a "hopelessly weak" Sunak. Criticising Sunak for not sacking Zahawi, he argued the PM was being "overwhelmed at every turn"
• Sunak said he believed in "proper due process", after asking his ethics adviser to investigate whether Zahawi broke ministerial rules. He accused Starmer of "political opportunism" for urging him to appoint an ethics adviser, then wanting a decision before the case had been investigated
• SNP Westminster leader Stephen Flynn said the issue of Zahawi's tax affairs was "now a matter of the prime minister's own integrity and accountability". He suggested that people in Scotland "may well just consider the Tory party to be a parcel of rogues"
• Sunak again defended his position, saying he was standing up for "proper due process, that's why we have an independent adviser"
• After PMQs, Downing Street was asked whether Rishi Sunak had ever paid a tax penalty of his own - a question it declined to answer

Image source, House of Commons

The prime minister now faces calls from Labour to make clear whether he has ever paid a tax penalty, like Conservative chairman Nadhim Zahawi did.

During a regular briefing for journalists, Downing Street repeatedly declined to give an answer.

The PM's press secretary said: "You wouldn't expect me to get into the prime minister's tax affairs. They are confidential. The tax affairs of an individual, irrespective of who they are, are confidential."

Sunak would, however, publish his tax return "in due course". But No 10 would not commit to the publishing of six years of the PM's tax returns, as David Cameron did.

BBC political editor Chris Mason says scrutiny over tax arrangements is already "to a degree" tilting from Zahawi to Sunak.

He says there is always a "political awkwardness around people of astonishing wealth in high office". Plenty of people might admire their "entrepreneurial zeal", he adds. But their wealth means there is an "other worldliness" about their tax affairs - however proper they are - that many people will not be able to relate to.

Chris Mason also notes that last year Sunak - when chancellor - was embroiled in a political row over his wife's non-dom tax status.

Citing Nadhim Zahawi's tax affairs, and the prime minister's refusal to sack him, Sir Keir Starmer suggested Sunak was "hopelessly weak". He asked whether his opponent's job was "too big for him".

The PM said he was someone who stood by his principles - unlike Starmer, who he accused of "petty politics". Watch their exchange above.

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BBC Two's lunchtime political programme

"I find it surprising that all of these prime ministers did not know what was going on with Zahawi," shadow attorney general Emily Thornberry told the BBC a short time ago, in reference to the former chancellor's tax affairs.

"The guy should go, and he shouldn't have been appointed in the first place," she added.

But Trade Minister Andrew Bowie countered: "We would much rather be focusing on the issues that matter to the British people." The government representative said the formal investigation process needed to happen before any conclusions could be reached.

Image source, Reuters

A lot of discussion today was on the tax affairs of Tory chairman Nadhim Zahawi. Here's a timeline.

• Nadhim Zahawi co-founded YouGov in 2000 - which became a public company in 2005
• Zahawi was chief executive of the polling company until 2010, at which point he was elected for Stratford-upon-Avon at the general election
• He joined Theresa May's government in the 2018 reshuffle as children's minister

• Zahawi became business minister in 2020, under Boris Johnson - and was later given responsibility for delivering the Covid-19 vaccine programme
• On 5 July 2022, Zahawi became chancellor, after the resignation of Rishi Sunak from that role. It was during this period that Zahawi entered into a multi-million pound tax settlement with HMRC - including a penalty
• Zahawi supported Liz Truss in the first Tory leadership contest of 2022, and then backed Rishi Sunak's bid to be leader

• On 25 October 2022 new prime minister Sunak appointed Zahawi as the chairman of the Conservative Party. It is not clear what he knew about Zahawi's tax issues at the time - which Zahawi later described as an error that was "careless and not deliberate"
• On Monday, Sunak announced that he'd asked his independent ethics adviser to look into Zahawi's tax affairs

Reality Check

Asked at PMQs about failures in the probation service - which were highlighted in a report into the murder of Zara Aleena - Rishi Sunak pointed to an “increase in the number of senior probation officers”.

As of September 2022 – the latest data, external available – there were 1,309 senior probation officers in England and Wales. This was an increase of 85 on the previous year and more than double the number seen in 2015.

In total, there were 18,366 full-time staff members - with different levels of experience - working in the probation service. This has increased in recent years, but so have the numbers leaving.

In the year to September 2022, over 2,100 people had left the probation service. There were almost 2,000 probation officer posts unfilled.

Image source, Family handout/Metropolitan Police

During PMQs we heard Sir Keir Starmer reference the murder of Zara Aleena and the failings of the probation service to release the man who killed her.

Zara died last June after being brutally attacked by Jordan McSweeney while walking home in east London from a night out with a friend.

McSweeney had been released on licence from prison just nine days earlier. A report this week found he had been wrongly assessed as "medium risk" by staff who were under "mounting pressure" at the time.

Zara's family said their relative would "still be alive today if probation had done their jobs better", accusing the service of having "blood on its hands". Starmer said this remark also applied to the government.

In the Commons, Sunak called the murder a "terrible crime" and said steps were being taken to address issues identified in the report.

McSweeney was jailed for life last month and ordered to serve a minimum of 38 years in prison.

• You can read more about the report here

That's a wrap on this week's PMQs, although the pressure surrounding Nadhim Zahawi over his tax affairs shows no sign of easing.

As expected, this week's back and forth between Rishi Sunak and Sir Keir Starmer referred to Zahawi, with testy exchanges and accusations of weakness and pettiness levelled at both party leaders.

Starmer opened his questioning by pressing the PM on failings that could have prevented the murder of Zara Aleena in London last summer.

Labour's Andy Slaughter raises last week's execution by Iran of his constituent, Alireza Akbari. He says the UK made little effort to protect him or to protest against the death of a British national, beyond "trifling steps".

What sanction, Slaughter asks, will the government impose on the Iranian regime - and why won't it follow the US and the European Parliament in proscribing Iran's Revolutionary Guard as a terrorist organisation?

Sunak says Iran is continuing to show a disregard for "basic human dignity" - adding that it must provide Akbari's family with answers about his death and burial.

He says the government has taken action, raising the execution with Iran's chargé d'affaires in London and the foreign ministry in Tehran - and adds that sanctions have been imposed on several officials connected with the case.

Tory MP Sir James Duddridge asks if Rishi Sunak is committed to continue helping people with the cost of living, not just this winter but also next winter.

In response Sunak explains the government's commitment to support all families this winter with £900 worth of support.

He goes onto explain that next year "as energy price guarantee evolves" the government will support families with around £500.

Sunak adds: "This comes on top of record increases in the National Living Wage worth about £1,600 and supporting our pensioners and the most vulnerable by inflating their benefits and pensions with inflation."

Moving on to questions from other MPs now, and veteran Tory MP Dr Liam Fox talks about innocent civilians "being murdered" in Ukraine and families freezing across the country due to the Russian conflict.

He urges the UK, which he says has shown great leadership, to commit to making sure the PM uses "every means at his disposal" to continue defending "whole world order".

Sunak replies by saying UK and allies must "accelerate" efforts to ensure Ukraine wins the war.

He acknowledges the news that Germany has agreed to send its Leopard 2 tanks.

Sunak's own taxes could be scrutinised soon - if he publishes returnspublished at 12:33 Greenwich Mean Time 25 January 2023

12:33 GMT 25 January 2023

Ione Wells
Political correspondent

A hint of the next issue coming down the road for Rishi Sunak?

Rishi Sunak decided to address his comments last week - that Nadhim Zahawi had addressed questions about his tax affairs in full - head on in PMQs today.

He said more information (the fact Zahawi paid a penalty to HMRC) had come to light since he spoke last week and that’s why he has asked the government’s ethics adviser to investigate.

While he got cheers from his MPs for saying he believes it’s fair to allow due process, it was uncomfortable to be answering questions about the ethics of his own MPs again.

Perhaps more uncomfortable, personally, though were the hints at a potential next challenge for Rishi Sunak.

The Labour leader Sir Keir Starmer asked speculatively why the prime minister may not want to talk about tax avoidance and family connections.

The SNP Westminster leader Stephen Flynn asked whether people seeking to avoid tax should simply “apply for non-dom tax status.”

Both are alluding to revelations last year that Sunak’s wife had claimed non-dom tax status to avoid UK tax on overseas income.

Sunak has promised to publish his tax returns at some point, and No 10 have hinted this will be soon. He’s said he wants to be transparent about this, but the publication of them may, at least temporarily, turn eyes away from one very wealthy Tory MP’s taxes to the prime minister's own.

Sunak replies saying he believes in due process and insists that it's "right" the independent adviser is allowed to do his job.

Flynn says the PM has failed to answer his question.

He says it's a matter of Sunak's own integrity and accountability that he's now backing Zahawi despite his tax penalty and backing former PM Boris Johnson despite his appointment of BBC chairman Richard Sharp.

People in Scotland, Flynn suggests, will conclude the Tory party is a "parcel of rogues".

Sunak responds by explaining what the government has done to support the most vulnerable in society.

He says: "Just this winter helping families with £900 for their energy bills, raising the national living wage to record levels and ensuring that our pensioners get the support they need, that's what this government is doing to ensure financial security in this country."

Turning to the SNP's question, Westminster leader Stephen Flynn asks what advice the PM has for individuals seeking to protect their finances.

He notes the recent controversies around Nadhim Zahawi and allegations that the BBC Chairman helped Boris Johnson apply for a loan.

Sunak says "the difference between him [Starmer] and me is I stand by my values and principles".

He says "when anti-Semitism ran rife" in the Labour Party, Keir Starmer continued to sit next to Jeremy Corbyn on the Labour front bench.

"He has no principles, just petty politics," he finishes.

Starmer rounds off his questions by saying Sunak's failure to sack Zahawi shows "how hopelessly weak he is".

He accuses the PM of overseeing chaos and being "overwhelmed at every turn".

Is the job "just too big for him?"

Sunak responds again by saying that with regard to the appointment of Zahawi, Sunak says "no issues were raised with me".

He says: "Since last week more information has come forward and that is why I've asked the independent advisor to look into the matter.

"It is right that we fully investigate this matter and establish all the facts."