The Opposition leader repeatedly denied breaking the laws in a televised statement, shown on Monday, May 9, as he faces pressure over a curry and beer “gathering” in Durham last year, which took place during campaigning for the Hartlepool by-election.
He accused the Conservatives who said he broke lockdown rules of “trying to feed cynicism to get the public to believe all politicians are the same”.
The British public deserves politicians who “put the country first rather than themselves”, Sir Keir continued.
13 pictures as Sunderland fans celebrate promotion in the city centre
13 of your fan pictures ahead of Sunderland's League One play-off final at Wembley
13 fantastic pictures from the STACK at Seaburn as Sunderland clinch play-off final win
Tributes paid to ‘massive’ Sunderland fan Tony Staplin after tragic death in County Durham crash
Uncertainty over future and ownership of former Sunderland Travelodge in High Street West
“But if the police decide to issue me with a fixed penalty notice I would of course do the right thing and step down,” he said on Monday.
“This matters. It matters because the British public deserve politicians who think the rules apply to them," his statement added.
“They deserve politicians who hold themselves to the highest standards. And they deserve politicians who put the country first rather than themselves. They will always, always get that from me.”
After his statement, Sir Keir was asked by Sky News political editor Beth Rigby why it took him so long to set out his position.
"Unlike those at Downing Street, I don’t think those that make the laws can then simply breach them and not take action.
“I believe that if you’ve made a law you should respect the law. And if you’re found to be in breach of it, you should step down and that’s what I’ve set out clearly this afternoon.”
Labour’s deputy leader Angela Rayner also said she will resign if she is fined.
She added: “I’ve always been clear that I was at the event in Durham working in my capacity as deputy leader and that no rules were broken.
“Eating during a long day’s work was not against the rules. We have a Prime Minister who has been found to have broken the rules, lied about it and then been fined.”