Sir Keir Starmer is preparing to address Labour MPs tonight as the Prime Minister battles to get his leadership reset back on track.
Sir Keir, who is currently facing fury from the hard left over Labour's plan to elect a replacement for Angela Rayner as deputy leader, will come face-to-face with the parliamentary party at 6pm.
Just weeks ahead of Labour Party Conference in Liverpool, Sir Keir also risked infuriating more of his disgruntled backbenchers.
The Prime Minister is refusing to guarantee Ms Rayner's successor will secure a Cabinet role.
"David Lammy is Deputy Prime Minister and will remain Deputy Prime Minister," the Prime Minister's spokesman said.
A Labour source added: "This is a party role and has party responsibilities."
However, Sir Keir has struggled to implement his reset since returning from the summer recess.
Ms Rayner's resignation sparked a quick-fire reshuffle on Friday, with Yvette Cooper being placed as Mr Lammy's replacement as Foreign Secretary and Shabana Mahmood filling her shoes in the Home Office.
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Sir Keir will address Labour MPs tonight
| PAMeanwhile, a key aide to the Prime Minister left his role in No10 just two weeks after entering Downing Street.
Tom Kibasi, a former think tank boss, joined No10 having previously been hailed as Sir Keir's "strategy architect" in his successful 2020 leadership race.
However, Mr Kibasi is not the first of Sir Keir's aides to have left No10.
The Prime Minister's first Chief of Staff, Sue Gray, was forced out after losing a power struggle with Mr McSweeney last October.
Nin Pandit and Matthew Doyle have also joined Ms Gray out the door.
Candidates for deputy leader of the Labour Party will have "to be someone outside London and it definitely needs to be a woman", according to former deputy leader Baroness Harman.
She told BBC Radio 4 that it "definitely" needs to be a woman, adding: "I don't think we can have a male Prime Minister, a man as Deputy Prime Minister and a male deputy leader of the party."
Home Secretary Shabana Mahmood has already ruled herself out for the role, telling Sky News that her "top priority is securing our borders".
Home Secretary Shabana Mahmood has ruled herself out of the race
| PASafeguarding Minister Jess Phillips has also ruled herself as well as Lisa Nandy, who stayed on as culture secretary during the reshuffle.
Possible candidates include Emily Thornberry, who was removed by Sir Keir when she was shadow attorney general.
Other individuals expected to stand include Louise Haigh and Lucy Powell, who was removed as Commons leader in the reshuffle.
Stella Creasy, Sarah Owen, Dawn Butler, Meg Hiller, and Anneliese Dodds are all considering standing.
Mayor of Greater Manchester Andy Burnham raised concerns about the inclusion of the cabinet following Ms Rayner's exit.
He said: "I am concerned about the balance, and I think you know, we need to use the deputy leadership contest to discuss some of these things.
"I see good people, good MPs, losing the whip, people like Rachael Maskell. That doesn't seem fair to me. It didn't happen in the governments I was in, in Gordon Brown's Government or Tony Blair's Government.
"You know, we need a different style here, so that everyone is included and we pull together."