When Sir Keir Starmer first approached Sue Gray early last year to be his chief of staff, he believed the veteran civil servant would bring her long Whitehall experience to Labour’s preparations for government.

As the brains behind Starmer’s leadership campaign, McSweeney (47) is credited with having brought the prime minister to power. He entered No 10 as head of political strategy, in charge of charting the party’s path to another victory in five years’ time.

Morgan McSweeney, who led Labour’s general election campaign, is reported to have clashed with outgoing chief of staff Sue Gray.

Sue Gray has quit her role as Prime Minister Sir Keir Starmer's chief of staff, saying she "risked becoming a distraction". She had been caught up in rows over pay, after the BBC's political editor revealed her salary was higher than Sir Keir's,

Sue Gray’s departure has triggered a wider reshuffle of Number 10, and Morgan McSweeney is set to take over her role

Sue Gray has quit her role as Prime Minister Sir Keir Starmer's chief of staff. A Downing Street spokeswoman confirmed Ms Gray will take up a new role as the PM's envoy for nations and regions. This breaking news story is being updated and more details will be published shortly.

Sue Gray has quit her role as Sir Keir Starmer's chief of staff, plunging his Government further into crisis. The former civil servant had been the Prime Minister's top aide in No10 since Labour's general election victory in July.