Labour leader Sir Keir Starmer has pulled out of a keynote speech he is due to give today – as pressure mounts on him over so-called ‘beergate’ claims.

After being a hugely vocal critic of Prime Minister Boris Johnson and the ‘partygate’ Downing Street gatherings during COVID lockdown, Sir Keir is now facing allegations that he too had a beer in a room with colleagues.

Sir Keir has said he was working and stopped to eat when he was filmed having a drink in Durham in April last year – at a time when rules banned household mixing indoors, apart from working.

Durham Police are now investigating the event after a leaked memo obtained by the Mail of Sunday revealed it was in fact pre-planned, in contrast to Labour’s earlier claims it was decided on the night as “nowhere served food”.

And now, the Institute for Government think tank has confirmed Sir Keir has pulled out of its event to discuss the “challenges the country faces”.

Labour did not offer an explanation as to why its party’s leader was no longer attending the gathering, which was timed to precede Tuesday’s Queen’s Speech.

But Monday’s Daily Mail claims Sir Keir is “running scared”.

However, Labour’s Lisa Nandy told Sky News the Tories were simply trying to “sling mud”.

She called the Labour leader, who is a former Director of Public Prosecutions, “Mr Rules” and told Sophy Ridge on Sunday: “It is frankly absurd of the Tories to claim that this in any way equates to a prime minister who was under investigation by the police for 12 separate gatherings which included karaoke parties, bring your own bottle parties, pub quizzes, suitcases full of wine being smuggled through the back door.

“The prime minister lied about that, he denied that they happened, denied that he was there. He came clean and he laughed about it.

“I’m absolutely confident that no rules were broken, not least because this was investigated last time the Conservatives tried to sling mud at us and Keir Starmer was found to be completely in the clear.

“This is a guy who self-isolated six times during the pandemic.”