Sir Jeremy Heywood, former cabinet secretary and civil service head, has died of cancer aged 56, Downing Street has announced.
Sir Jeremy was cabinet secretary from 2012 until 2018 and head of the civil service between 2014 and 2018.
PM Theresa May said “he worked tirelessly to serve our country” and is a “huge loss to British public life”.
Labour’s Yvette Cooper said Sir Jeremy had done “a lot to hold government together at very difficult times”.
Sir Jeremy first joined the civil service in 1983 and Sir Mark Sedwill, his successor as cabinet secretary and head of the civil service, described him as an “exemplary public servant”.
“We will miss him more than we can say,” Sir Mark said, adding the country “will be the poorer without his advice, leadership and extraordinary insight”.
The prime minister described the news as “extremely sad” and said her thoughts were with Sir Jeremy’s family.