Labour is confident it can prove Sir Keir Starmer did not break lockdown rules after he pledged to offer his resignation if issued with a fixed penalty notice by police.

Sir Keir has come under pressure over an event in Durham in April 2021 with party colleagues when he was filmed having a drink and a takeaway curry was ordered.

In a dramatic statement on Monday, the Labour leader said he would do the “right thing” if issued with a fine for breaking COVID rules.

The move places his future in the hands of Durham Police after it was announced last week officers would reopen an investigation into the event.

Politics Hub: PM promises to combat ‘aftershocks of COVID’ in Queen’s Speech

However, Labour sources believe they have proof that it was a work event and that those present were taking a break to eat while working late on preparations for the Hartlepool by-election.

A report in the Guardian newspaper stated that the party has compiled time-stamped logs from messaging chats, documents and video edits showing they carried on working until 1am – well after when the takeaway was delivered.

It added that detectives investigating the alleged breach of lockdown rules are considering interviewing the Labour leader face to face.

“We have been totally clear that no rules were broken. We will provide documentary evidence that people were working before and after stopping to have food,” a Labour source told the Guardian.

‘No laws were broken’

Speaking on Monday, Sir Keir, who has been a fierce critic of Boris Johnson’s rule-breaking in Downing Street, said he was “absolutely clear that no laws were broken” in his case.

But he added: “If police decide to issue me with a fixed penalty notice, I would of course do the right thing and step down.”

Pressed on whether he would quit if it was determined that there was a breach of the rules but he is not issued with a fine, Sir Keir said he had not broken the rules and added: “The penalty for a COVID breach is a fixed-penalty notice, that’s a matter of law, and I’ve set out what the position is in relation to that.”

Labour’s deputy leader Angela Rayner, who was at the event too, also said no rules were broken and made a similar pledge that she would quit if fined.

At the time, COVID rules banned household mixing indoors, apart from working.

Over the weekend a leaked memo obtained by the Mail on Sunday revealed the meal was pre-planned, in contrast to Labour’s earlier claim that it was a decision on the night as “nowhere served food”.

On Monday, Sir Keir pulled out of a planned think-tank event as pressure mounted.

But in a hastily-arranged news conference later that day, the Labour leader agreed to face broadcast journalists to answer growing questions about how he might respond if found to have broken the law.

‘I believe in honour’, says Starmer

In a statement, he sought to draw a distinction between his position and that of Mr Johnson, who has already received a fixed penalty notice after a Met Police investigation into alleged lockdown breaches in Downing Street and Whitehall in 2020 and 2021.

That investigation, in which more than 50 fines have already been announced, is continuing.

Sir Keir said: “I believe in honour, integrity and the principle that those who make the laws must follow them.

“I believe that politicians who undermine that principle undermine trust in politics, undermine democracy, undermine Britain.

“I am absolutely clear that no laws were broken – they were followed at all times.

“I simply had something to eat while working late in the evening as any politician would do days before an election.

“The prime minister has chosen not to resign, notwithstanding that, not only has he broken the law that he made, but 50 fines being imposed in relation to the workplace that he is responsible for.

“That is his choice. But it’s very important that the public don’t think that all politicians are the same and that is why I have set out my position in terms of honour and integrity.”

Speaking on Sky News on Tuesday, Policing Minister Kit Malthouse said Durham Constabulary will meet “high standards” regardless of any alleged pressure on them as they investigate the Labour leader.

“Durham police will operate professionally to the high standards we expect of them irrespective of what the external goings-on are around this case,” he said.

“We need to leave them the space and time to do their job.”

The COVID-19 Bereaved Families for Justice UK campaign group, which has been critical of the government’s pandemic policies, tweeted: “This is the right decision by Keir Starmer and in contrast to Boris Johnson, shows integrity, decency and respect to the bereaved.”