Keir Starmer was plunged into a fresh political crisis after his chief of staff resigned following a power battle at the heart of Government.

Former civil servant Sue Gray said the “commentary” about her position had become a “distraction”.

But Tory leadership candidate Robert Jenrick said it “feels as if she’s fleeing a sinking ship”.

Ms Gray was on Sunday replaced by Sir Keir’s chief strategist, Morgan McSweeney, who is said to have repeatedly clashed with Ms Gray since Labour took power less than 100 days ago.

Mr Jenrick told the Daily Express: “Labour’s government is in chaos. Internally, it is ridden with scandal.

“Starmer has lost or been forced to kick out seven rebellious MPs. Number 10 has been beset by briefings and petty squabbles over who sits where and who controls the Prime Minister’s diary. His special advisors are in open revolt over who gets paid what while Sue Gray banked more than the Prime Minister.

“Her resignation was no surprise. After months of infighting and a series of terrible decisions for the people of Britain, it feels as if she’s fleeing a sinking ship.

“Starmer has no national security advisor. He’s had to replace his private secretary. And the Cabinet Secretary – the country’s most senior civil servant – is rushing out the door. This is free-fall.”

Fellow leadership candidate James Cleverly added: “Labour’s first 100 days have been a disaster, and their civil war continues with the loss of Sue Gray.

“I will waste no time holding this chaotic Labour government to account, making it clear the Conservatives are ready to govern again and set the country back on track.”

Ms Gray was accused of wielding too much power over Number 10 and was simultaneously blamed for Labour’s failure to avoid controversy over freebies and donations.

She has also been held responsible for Labour’s shambolic start in their first 100 days.

And the former civil servant’s £170,000 salary was leaked after she told other advisers to take a pay cut to serve in Government.

Senior figures even discussed the possibility of offering Ms Gray a peerage in a bid to ease her out of Downing Street.

Highlighting how split Sir Keir’s operation was, Ms Gray only attended her first meeting with the Number 10 political team last week.

And Cabinet ministers are said to have become increasingly frustrated at the chaos at the heart of Government.

Rumours swirled around Westminster on Sunday morning after a Cabinet minister dodged questions over her future.

Asked if Ms Gray would still be in her role in a month’s time, Science and Technology Secretary Peter Kyle said: “All I can say is that Sue Gray is an outstanding public servant and I’m so proud of the work she has done, because I’ve seen it up close.”

Pressed on whether she was still in post at that moment, Mr Kyle added: “I can’t comment on any public servant, because it’s not appropriate for me to comment on public servants who cannot answer for themselves.

“But what I will say is her public service and what she has done for this country and on behalf of this country is something that I and this Government is very proud of.”

Labour ministers and officials had claimed, in the wake of the General Election result, that “the adults are back in the room”.

Ms Gray has been given a new role as the Prime Minister’s envoy for the regions and nations.

In a statement, Ms Gray said: “It has been an honour to take on the role of chief of staff, and to play my part in the delivery of a Labour Government.

“Throughout my career, my first interest has always been public service.

“However, in recent weeks it has become clear to me that intense commentary around my position risked becoming a distraction to the Government’s vital work of change.

“It is for that reason I have chosen to stand aside, and I look forward to continuing to support the Prime Minister in my new role.”

Sir Keir thanked Ms Gray for “all the support she has given me, both in opposition and government, and her work to prepare us for government and get us started on our programme of change”.

“Sue has played a vital role in strengthening our relations with the regions and nations. I am delighted that she will continue to support that work,” he added.

Ms Gray’s departure has triggered a wider reshuffle of the Downing Street operation. She will be replaced as chief of staff by Morgan McSweeney.

Political director at Number 10 Vidhya Alakeson and director of government relations Jill Cuthbertson have been promoted to deputy chiefs of staff.

Nin Pandit, director of the Downing Street Policy Unit, has been appointed principal private secretary to the Prime Minister, and former journalist James Lyons will join to head up a new strategic communications team, Downing Street said.

The government’s list of planned announcements, known internally as “the grid”, had been under the command of Sue Gray, but will now be under the control of the No10 communications team, where some believe it should always have been.

The Labour psychodrama even prompted fury from some of the party’s own MPs, with John McDonnell posting on X: “We’re facing the potential of a war setting the Middle East alight, already thousands being killed in Lebanon and what is the focus of the boys around Keir Starmer’s office, carving up Sue Gray and grabbing her job and salary.

“Words fail me.”