Keir Starmer hit by another resignation as pressure mounts on PM over Mandelson scandal

He said: “I have decided to stand down to allow a new No 10 team to be built. I wish the PM and his team every success.”

Mr Allan previously served as Tony Blair's deputy press secretary following New Labour's landslide victory in 1997, working alongside Alastair Campbell in No10.

Despite being a leading figure in the New Labour project, Mr Allan also served on the board of the gender-critical Sex Matters group before returning to Downing Street.

Following his first stint in No10, Mr Allan founded the public relations consultancy firm Portland Communications in 2001.

He sold a stake in the company for an estimated £20million in 2012.

Mr Allan returned to Downing Street following the resignations of James Lyons and Steph Driver.

However, Mr Allan's resignation came just hours after the Prime Minister's chief of staff Morgan McSweeney quit over the appointment of Lord Mandelson as the UK's Ambassador to the US.

Mr McSweeney took "full responsibility" for his advice to make Lord Mandelson Britain's man in Washington despite his relationship with convicted paedophile Jeffrey Epstein.

The 48-year-old Irishman was widely regarded as a key architect of Sir Keir's landslide victory in 2024.

Mr McSweeney also won the first power struggle of Sir Keir's premiership, seeing off ex-civil servant Sue Gray.

In an address to No10 staff this morning, the Prime Minister praised Mr McSweeney for his work during his 491-day stint as No10 chief of staff.

Sir Keir said: “I’ve known Morgan for eight years as a colleague and as a friend.

"We have run up and down every political football pitch that is across the country.

"We’ve been in every battle that we needed to be in together.

"Fighting that battle. We changed the Labour Party together.

"We won a general election together. And none of that would have been possible without Morgan McSweeney.

“His dedication, his commitment and his loyalty to our party and our country was second to none. And I want to thank him for his service.”

Despite Scottish Labour leader Anas Sarwar being set to call for Sir Keir's resignation, the Prime Minister today ruled out quitting.

In a briefing to journalists, a No10 spokesman said: “He is getting on with the job in hand and delivering change across the country.”

The spokesman added that Sir Keir remains “upbeat and confident” following a speech to staff in Downing Street this morning.

Despite speculation about further resignations, the Prime Minister also retains the support of his Cabinet.

GB News understands that No10 is not expecting more resignations today.

The Prime Minister will also face a crunch meeting with backbench Labour MPs at 6pm tonight.