Dominic Casciani
Legal correspondent, reporting from court

More now on the announcement from Prince Harry's lawyer that the royal won't attend court today.

The judge had directed that the Duke of Sussex should be available to start giving evidence this afternoon, in case opening statements from both sides were completed with plenty of court time left.

The key points of Harry's case will take three hours to go through and MGN's lawyers have said they need very little time to rebut them.

David Sherborne, representing the claimants, said Prince Harry has flown in from Los Angeles, after his daughter’s birthday, but he added: "He is in a different category from the three other claimants due to his travel and security arrangements.

"It was never anticipated that the openings would not take the whole day."

Mr Justice Fancourt replied: "It was anticipated that they might - which is why I directed that the first witness should be available."

Andrew Green KC, for the Mirror Group, protested. "I have to cross-examine [Prince Harry] on 33 articles and that cannot be done in one day," he said. "I need one and a half days. That is not unreasonable."

"I am not going to restrict you to a day," replied the judge, indicating that he will make the court - and the Duke - sit for longer hours on Tuesday and Wednesday, if necessary.

Tom Symonds
Home Affairs correspondent, reporting from court

Lawyers for the Mirror Group have accused Prince Harry’s side of “wasting time” by not having him available to give evidence today.

Andrew Green said it was “absolutely extraordinary we were told just last week that he is not available for day one of his own trial".

It’s not the first time the two sides have clashed over the management of the case. David Sherborne, for the claimants, has been criticised several times in recent weeks for the length of his submissions - he said this morning he needs three hours to make an opening statement.

MGN’s lawyers asked for Prince Harry to be available today to give evidence but the BBC was told on Friday by his legal team he would not be.

Sean Coughlan
Royal correspondent, reporting from court

Apart from the specifics of the hacking claims, there will be huge interest in what else Prince Harry might reveal during questioning this week.

How will he react to being pushed back on his evidence? Will he get irritated, getting the type of direct questioning that royals usually avoid?

In terms of Prince Harry’s travel plans in coming from the US to the UK, it was his daughter Lilibet’s birthday yesterday.

Last month at the Coronation, Prince Harry had rushed back to California for his son Archie’s birthday.

Sean Coughlan
Royal correspondent, reporting from court

The big build-up to Prince Harry’s court appearance continues – but he’s currently not expected to be giving evidence today, that looks set to begin tomorrow morning.

Although that seems to be irritating the Mirror Group lawyers that he can’t be questioned today, giving them more time to personally scrutinise his claims over hacking.

For the public there’s no escaping that Prince Harry’s presence – giving evidence face-to-face in the witness box – is going to be the big spectacle here, rather than the machinery of legal processes.

It’s where courtroom drama collides with the royal soap opera.

Jemma Crew
Reporting from court

The press benches are packed in the courtroom today, with about 30 journalists here, while the desks in the overspill annexe next door are full.

There are also some members of public in attendance.

But those wanting a glimpse of royalty today will be disappointed – Prince Harry’s lawyer has just told the court he will not be attending today.

Prince Harry will not be appearing in court today, his lawyer David Sherborne has just told the court.

The judge in this case, Mr Justice Fancourt, ultimately needs to decide, on the balance of probabilities, who is telling the truth. He will then apply the law and make a judgement.

There are still several court sessions to take place after today, with this case starting on 10 May and likely to last seven weeks in total.

Today’s proceedings have got under way at the High Court.

We'll be hearing from Prince Harry's lawyer David Sherborne shortly after some housekeeping matters are sorted out, so stay with us as we bring you the key developments.

Image source, Reuters

We've just spotted lawyer David Sherborne, who is representing Prince Harry and the other claimants, arriving at the High Court in the last few minutes.

The hearing is expected to get under way shortly, so stay with us as we bring you the latest.

Not in this case, no. This isn’t a criminal case, it’s a civil one. That means there’s no jury, and it’ll be a judge who decides the outcome of the case.

If Prince Harry and the other claimants win, they could be awarded money - known as damages - which typically could be anything from £1 upwards.

Image source, Reuters

This is a civil case, rather than a criminal case, being heard before a judge. It’s rare for a civil cases to have a jury, with defamation trials the main exceptions.

Judges play an important role in managing civil cases like this, external once they’ve started, ensuring they proceed fairly as well as efficiently.

They decide on the outcome by finding facts and applying the relevant law. Once they’ve heard the evidence from all the parties involved in the case, they deliver a judgement.

If wrongdoing is found, they must then decide the appropriate action.

This can be damages, costs or an injunction (an order requiring the other party to do or not do something). Or a combination of all three.

Mirror Group Newspapers deny allegations of voicemail interception in the cases being examined here, and claim some of the cases being brought are beyond a legal time limit.

MGN has defended some of its reporting by alleging a "public interest", or claiming published information was "limited and banal".

In the case of Prince Harry there are 33 articles central to his claims, but MGN’s lawyer Andrew Green KC says in written submissions that the publisher denies 28 of them involved phone hacking or other unlawful information gathering.

He says stories instead came from a variety of other sources - including other members of the Royal Family. Green added that it was "not admitted" the five remaining articles contained unlawful information gathering.

The allegations concern stories dating back, in some instances, more than 20 years.

The claimants [those who believe their phones were hacked] allege that journalists from the Daily Mirror, Sunday Mirror and The People newspapers obtained private and confidential information about their lives through a variety of illegal means.

They believe that journalists exploited a (now-closed) gap in the security of mobile phones which allowed them to access the voicemail of their targets.

By listening to messages left by friends and family, they were able to find out about the lives of the people they wanted to write about.

Journalists also allegedly used private investigators to trick others into handing over confidential information about the targets - everything from financial details to medical information. Read more here.

Image source, Reuters

Prince Harry, and three other people, are taking a newspaper publisher to court, alleging information about them was illegally gathered to generate stories.

They believe journalists from the Daily Mirror, Sunday Mirror and The People exploited a security gap to access their voicemails and hear messages left by friends and family.

Mirror Group Newspapers has previously admitted phone hacking took place, but says it didn’t in these cases.

This is a test case - if Harry and the other claimants win, the judge will use it to set the level of damages (amount of money) MGN could pay in other cases from other celebrities.

This is one of three major cases that Prince Harry has made against tabloid newspapers, all alleging unlawful information gathering.

He is also suing News Group Newspapers (NGN), publisher of The Sun, for alleged hacking. Its lawyers are trying to have the case thrown out by arguing that Harry has run out of time to bring it to court.

The paper's owners have long admitted hacking took place at the News of the World before it closed down in 2011 - but never conceded it happened at The Sun.

Separately, the Duke is one of several people who allege Associated Newspapers, the publisher of the Daily Mail and Mail on Sunday, hired private investigators to bug their phones, homes and cars.

The newspaper group vehemently denies the allegations. The future of these cases will be decided later this year.

There's already a flurry of activity outside the High Court this morning as we wait for Prince Harry's privacy case against the publisher of the Mirror newspaper to resume.

You’ll be able to see what's happening outside the court by clicking on the Play button at the top of this page, and we'll also be bringing you updates on that stream throughout the day.

We won't be able to film inside the court, but our colleagues are there and will be reporting the latest from the hearing.

Image source, Reuters

Members of the press are already in position outside The Rolls Building of the High Court in London this morning.

The case is due to resume in just over an hour, but we don't know as yet whether Prince Harry will make an appearance today.

Dominic Casciani
Legal correspondent

Allegations of voicemail interception first came to a head in 2006 when the News of the World's royal reporter and a private investigator were jailed.

That newspaper, owned by Rupert Murdoch, shut down in 2011 - and three years later its former editor followed them to prison.

Allegations had already mounted against the separate Mirror Group - the earliest dating to 1991.The company admitted some unlawful activity in 2014 - but blamed rogue reporters. Since then, it has faced 831 claims. Up to 230 cases are outstanding.

What makes Prince Harry's case different is this: He and the other three claimants want a judge to decide whether editors and executives - and not just frontline journalists - knew about hacking and covered it up.

The higher the allegations go, the worse the position could be for Mirror Group - and the greater the damages it would face if the cases are proven. And so the implications could be enormous.

Sean Coughlan
Royal correspondent

Image source, Getty Images

There's an element of theatre, more than legal process, that will grab the headlines when Prince Harry heads into the High Court this week - not least because it's so unusual to see a royal appearance in a witness box.

The last senior royal to give evidence in this way was in the 19th Century, when Edward VII, as Prince of Wales, appeared in two cases - one in a dispute over cheating in a game of cards and the other in a divorce case, in which the prince denied any "improper familiarity".

In 2002, Princess Anne appeared at Slough Magistrates’ Court to plead guilty after her dogs bit two children.

Dominic Casciani
Legal correspondent

Image source, PA Media

At the heart of the case will be 207 newspaper stories, published between 1991 and 2011 - some 67% of which were written about Prince Harry.

The claimants argue senior executives must have known about unlawful information gathering behind these stories and failed to stop it.

One of the key allegations in the case is that the TV presenter Piers Morgan, editor of the Daily Mirror between 1995 and 2004, knew of illegal activity. He has repeatedly denied involvement in illegal phone hacking.

The Duke of Sussex's lawyers want the court to consider a series of incidents which they say are evidence that Morgan not only knew about hacking but told others too.