Sir Jeremy Heywood, former cabinet secretary and civil service head, has died of cancer aged 56, just two weeks after stepping down from government.
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”.
Former PM Gordon Brown described him as “leader of exceptional ability and “unquestioned integrity”.
Former Labour minister Yvette Cooper said Sir Jeremy had done “a lot to hold government together at very difficult times”.
In a statement released on Sunday via Downing Street, his wife Suzanne paid tribute to a “wonderful father” who “crammed a huge amount into his 56 years”.
“He could light up any room or conversation,” she said. “For me, he was my wonderful partner for 22 years. We shared everything and I will miss him more than I can say”.
The cabinet secretary is head of the civil service and is sometimes described as the second most powerful person in the government after the prime minister.
Cabinet secretaries keep a low public profile but they sit next to the PM at cabinet meetings – and it is their job to ensure policies are put into action and offer advice on running the machinery of government.
Sir Jeremy had a long career at the top of government, serving four prime ministers in different roles.
He managed former Labour PM Tony Blair’s differences with his chancellor, organised Gordon Brown’s Downing Street, helped to hold the Conservative-Lib Dem coalition together, and, finally, supported Mrs May’s minority administration.
In 2003, he left Whitehall for a career in banking with Morgan Stanley, but was brought back into Downing Street by Mr Brown in 2007.
The former prime minister said in a statement: “The country has lost a leader of exceptional ability, unquestioned integrity and – as we saw in the way he fought his illness – remarkable courage.
“Jeremy Heywood was the most dynamic civil servant of his generation, a leader who inspired confidence, whose expertise was recognised by all and and whose impartiality was never in doubt.”
Mr Brown described him as a “unique civil servant” who “may not always have agreed with proposals from ministers but always had a positive and often better alternative to offer”.
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.
Sir Jeremy had been Cabinet Secretary since 2012 and previously served as principal private secretary to prime ministers Tony Blair and Gordon Brown, chief of staff to Mr Brown and Downing Street permanent secretary to former Conservative prime minister David Cameron.
He revealed earlier this year that he had been diagnosed with cancer in June 2017, but remained in post during a summer of political upheaval triggered by the shock general election result.
He took a leave of absence in June and announced on 24 October that he was stepping down.
Sir Jeremy was nominated for a peerage by Mrs May as Lord Heywood of Whitehall after his retirement in recognition of his distinguished service to public life.
His career was not without controversy, however. He was given the nickname “Sir cover-up” by tabloid newspapers after it emerged he had blocked the release of letters and phone calls between Mr Blair and then US president George Bush in the run-up to the Iraq war.
He said he felt “frustrated” by the label and argued that he had been the most transparent cabinet secretary ever.
He found himself at the centre of a number of political crises during his career – he was at Tory Chancellor Norman Lamont’s side with the pound crashed out of the European Exchange Rate mechanism in 1992.
He also faced criticism for breaking protocol by not taking minutes key meetings between Mr Blair and officials, which was revealed in evidence to the death of the weapons inspector Dr David Kelly.
Jeremy Heywood: UK’s former top civil servant dies}