Sir Keir Starmer has appointed Tony Blair’s former chief of staff as his national security adviser.
Veteran diplomat Jonathan Powell will begin the role next month, it is understood, taking over from Sir Tim Barrow, who has held the role since September 2022.
Mr Powell, who was No 10 chief of staff between 1997 to 2007, played a key role in brokering the 1998 Good Friday peace deal in Northern Ireland.
The appointment comes at a crucial time, given conflicts in the Middle East and Ukraine, and Donald Trump’s return to the White House in January.
Sir Keir said Mr Powell’s experience made him “uniquely qualified” to advise ministers on global security challenges.
After leaving Downing Street, Mr Powell has led a UK-based charity working on international conflicts and was made UK envoy to Libya in 2014 under former Conservative prime minister David Cameron.
Sir Keir brought him in to lead negotiations over the recently-announced deal to cede sovereignty of the Chagos Islands to Mauritius.
The agreement, which ministers have said they want to ratify next year, has faced a backlash from several senior Conservative MPs.