A top law professor has said the police will be looking at three main factors as they investigate Peter Mandelson over allegations of misconduct in public office.

Jeremy Horder, a professor of criminal law at the London School of Economics (LSE) is speaking to the Politics Hub about this offence, having written a book on it.

He tells Paste BN that the three factors are about whether somebody was "acting in a public capacity when they did whatever they did", whether there was "wilful wrongdoing" and thirdly, "if they did something wrong, and they did it knowingly, was that something that amounted to an abuse of the public's trust?"

He explains that the third point will be the "key element" in the police inquiry against Mandelson.

Horder adds: "That's quite a high threshold. So it's not as simple as saying, 'oh, well, I leaked some confidential material to a friend because it was gossipy or something'. 

"I mean, that's wrong, but it might not amount to an abuse of the public's trust. There would need to be something more than that."

Pushed on what exactly that would mean, the professor says: "It's a high bar for prosecuting misconduct in a public office.

"If there's any evidence of corruption, for example, if someone has sought to influence a private party for their own gain, so that would be significant."

He also admits that it is "not common" for this offence to be used in the UK because "most parliamentary wrongdoing is dealt with through parliamentary processes".

"Prosecuting someone for an offence with a maximum life penalty is not something to be taken lightly," he insists. 

But when somebody is prosecuted for a serious case, there is a "presumption of a sentence of imprisonment of some kind".

Away from the Lord Mandelson story, our political editor Beth Rigby has some interesting news from the Commons.

MPs have been voting on the two-child benefit cap tonight (see our 7.31pm post), but there's been some confusion within Reform.

Beth writes: "I hear that Robert Jenrick and Suella Braverman ended up WITH LABOUR MPs in the AYE lobby on lifting two-child benefit cap.

"A source tells me they 'got on their phones trying to get instructions from Farage as to whether they should be there or not'.

"They tried to leave at one point but got trapped as the doors were locked"

Beth says that a Reform source has confirmed to her that this happened and that it was a "genuine mistake".

Voting records from parliament show neither of them registered a vote, while all other Reform MPs voted against the bill.

The Tories are going to try and force the government to publish all documents relating to the vetting process carried out for Peter Mandelson, Paste BN understands. 

They hope to force ministers to publish the documents regarding the checks made into Lord Mandelson's relationship with Jeffrey Epstein before he took up the role of US ambassador in February last year. 

It's not something the government is keen to publish. 

So, to do that, they are using an arcane parliamentary procedure called a humble address. 

So, what is that exactly, and why does it matter? 

Our deputy political editor Sam Coates explains below...

A proposed law to scrap the two-child benefit cap has passed its first vote in the Commons.

MPs backed the bill 458 to 104, giving it a majority of 354 at its second reading.

Labour announced it would scrap the cap, which restricts welfare payments to those with more than two children, at the budget in November last year - in a bid to raise thousands of children out of poverty.

It wants the bill to come into effect from April, though it is subject to further scrutiny from MPs and peers.

The Conservatives have said they would not remove the cap, as they believe having children is a matter of "personal responsibility".

The policy was introduced in 2017 by the then-Tory government.

Reform UK previously said they would scrap the cap, then re-announced they would scrap the cap for British families, and today said they would reverse Labour's plans to scrap it in order to make the cost of a pint cheaper.

Previously, seven Labour MPs were suspended by the party after backing an SNP motion to scrap the cap in a vote in the Commons in 2024.

The government had at the time cited spending controls as a reason for not being able to ditch the policy immediately, indicating there would be no change without economic growth.

But this was later reversed last year.

The vote to scrap the cap was backed by Labour, the Liberal Democrats, independent MPs, the Greens, the SNP and Your Party.

Alongside the Tories and Reform, independent MPs Rupert Lowe and Patrick Spencer voted to keep the cap in place.

Sky's deputy political editor Sam Coates has been across the Peter Mandelson news today.

But how did we get to this point? Sam talks through the story in this video.

Kemi Badenoch says the police launching an investigation into Peter Mandelson over allegations of misconduct in public office was "inevitable" and is "right".

The Conservative Party leader tells Paste BN: "We should not let this distract us from the fact the prime minister has his fingerprints all over this.

"He knew all of the allegations, concerns and reports about Peter Mandelson, knew that he was a close friend, an associate, of a convicted paedophile, and he still gave him the biggest job in the Foreign Office, at a time when UK-US relations are at a critical point.

"That's what he chose to do, and he's got a lot of questions to answer."

This is in reference to what was known about Mandelson's public relationship with Jeffrey Epstein at the time he was chosen (December 2024) and then appointed (February 2025).

The revelations that have come out in recent weeks are a result of documents published by the US Congress, and Downing Street has said it was not aware of these allegations until they were made public in recent days.

Badenoch continues: "I think it is a national embarrassment.

"There are many people who should have been given that job, who should have been interviewed for that job, and they didn't get a chance. That's not right."

Asked if the police should interview Sir Keir Starmer, she says the "police will make this call".

But she adds: "If there is evidence that shows that there's something to do with the prime minister, then yes, of course."

Reacting to the news that the police have launched an investigation, a government spokesperson said: "The government stands ready to provide whatever support and assistance the police need."

The Conservatives will use a motion to call on the government to publish all papers relating to Sir Keir Starmer's appointment of Peter Mandelson as ambassador to the US, Paste BN understands.

Senior Tory sources have said the party will attempt to do this, by using an opposition day motion on Lord Mandelson.

This will be in the form of a "humble address" - a parliamentary mechanism designed to allow the opposition, the Tories, to be able to call for papers from the government to be published. 

Mandelson was selected for the role by the PM in December 2024, and took up the position in February 2025.

But he was then sacked by the PM seven months later due to growing allegations about his relationship with convicted paedophile Jeffrey Epstein.

Humble addresses are rarely used but are considered binding and therefore can be effective ways of forcing the government to publish information it would rather not disclose.

Peter Mandelson will face a criminal investigation into allegations that he leaked market sensitive information from Downing Street to Jeffrey Epstein, Paste BN understands.

It comes after emails appeared to show conversations between the pair about government and political matters while Lord Mandelson was serving as business secretary and the de-facto deputy prime in Gordon Brown's government.

Documents released by the US Department of Justice indicate Epstein was sent internal discussions from the heart of the UK government after the global financial crisis.

A number of opposition parties had called for a formal police inquiry.

Downing Street earlier said the Cabinet Office had referred how Mandelson handled sensitive government information while he was a minister to the Metropolitan Police.

Former prime minister Brown also said he had written to the force's commissioner, Mark Rowley, about Mandelson's contact with Epstein.

Mandelson has previously said: "I was wrong to believe Epstein following his conviction [in 2008 for procuring a child for prostitution and of soliciting a prostitute] and to continue my association with him afterwards. I apologise unequivocally for doing so to the women and girls who suffered."

In an interview with The Times carried out last week but published on Monday, Mandelson referred to a "handful of misguided historical emails, which I deeply regret sending", and described Epstein as "muck that you can't get off your shoe".

Sir Keir Starmer made a "grave, grave error of judgement" when he appointed Lord Mandelson as the UK's ambassador to the US, Nigel Farage has said.

An initial review by the Cabinet Office of documents released by the US Department of Justice has found that emails sent by Lord Mandelson to the paedophile financier Epstein likely contain market sensitive information relating to the 2008 financial crash and official activities thereafter to stabilise the economy. 

At a news conference in Westminster this lunchtime, the Reform UK leader was asked about efforts to strip Peter Mandelson of his title as a lord - before the peer announced his resignation.

Farage replied that he is "fine" with doing this, but that it "absolutely is not the issue of the day", pointing instead to accusations Mandelson shared market sensitive information with Epstein.

Watch: Nigel Farage speaks on Mandelson

Farage suggested that if Mandelson did give Epstein advanced notice of the bailout, the paedophile could have made "hundreds of millions out of that trade". 

The MP, who previously sat as a member of the European Parliament, explained: "When those bailouts happened, there was a massive immediate market shift. I watched it, it was huge. 

"Anybody that had that information, that access to money and funds are the kind that Epstein did... Well, if he made tens of millions out of it, he was lax because there was a chance to make hundreds of millions out of that trade."

But he added: "There is no direct insider trading law for bonds in quite the same way that there is for stocks. And that's been the case since 1981, the Insider trading Act. 

"But it is highly sensitive market information.

"So fine, talk about removing the title. But that really is, I think, a very small part of something that is much bigger, much more serious. And I'm not even sure that we know the full story yet."

How many more warnings did Starmer need?

Farage also hit out at Sir Keir Starmer and his chief of staff, Morgan McSweeney, over Mandelson's appointment as UK ambassador to the US, following Mandelson's two previous sackings from government.

He said: "How many more warnings did the prime minister or, indeed, Morgan McSweeney need? They have made a grave, grave error of judgement despite repeated warnings."

He also stated that his name is mentioned 37 times in the Epstein files - but insisted he never met the disgraced financier, and he didn't go to Epstein island.

Mandelson, who served most recently as UK ambassador to the US between February and September 2025, has strongly denied all wrongdoing. 

In a previous statement, he said: "I was wrong to believe Epstein following his conviction and to continue my association with him afterwards. 

"I apologise unequivocally for doing so to the women and girls who suffered."