Former Liberal Democrat leader Charles Kennedy has died suddenly at home, his family have said.
Mr Kennedy had served as an MP for 32 years, but was ousted from his Ross, Skye and Lochaber constituency last month as the SNP swept the board in the general election north of the border.
Police had been called out to his house in Fort William yesterday, after being alerted by the ambulance service.
The cause of is death is not yet known but it is not thought to be suspicious.
A statement released on behalf of his family said: “It is with great sadness, and an enormous sense of shock, that we announce the death of Charles Kennedy.
“Charles died at home in Fort William yesterday. He was 55. We are obviously devastated at the loss.
“Charles was a fine man, a talented politician, and a loving father to his young son. We ask therefore that the privacy of his family is respected in the coming days.
“There will be a post-mortem and we will issue a further statement when funeral arrangements are made.”
A spokesman for Police Scotland said: “Police officers attended an address at Fort William on Monday, June 1 to reports of the sudden death of a 55-year-old man. Police were notified by ambulance service personnel.
“There are no suspicious circumstances and our report will be submitted to the procurator fiscal.”
The father of one had been leader of the Liberal Democrats between 1999 and and January 2006 - when he stood down days after admitting he had a problem with alcohol.
His political career began in the Social Democratic Party, winning the Ross, Cromarty and Skye seat in 1983 to become the youngest MP of the time at the age of 24.
He took over as leader from Paddy Ashdown in 1999, and in that role was one of the most vocal critics of the invasion of Iraq in 2003.
In the 2005 general election he took the party to what was then one of its best general election results, winning 62 seats.
But just months later, following months of rumours about his drinking, Mr Kennedy dramatically admitted he had been receiving treatment for an alcohol problem and said he was calling a leadership contest.
While he had initially declared that he wanted to carry on he was forced to stand down in the face of the threat of mass resignations by senior colleagues.
Nick Clegg paid tribute to his predecessor as Liberal Democrat leader: “Charles’s untimely death robs Britain of one of the most gifted politicians of his generation.
“Charles devoted his life to public service, yet he had an unusual gift for speaking about politics with humour and humility which touched people well beyond the world of politics.
“He was a staunch internationalist and passionate believer in Britain’s role in Europe, yet he was a proud Highlander, Scot and British parliamentarian.
“He was one of the most gentle and unflappable politicians I have ever known, yet he was immensely courageous too not least when he spoke for the country against the invasion of Iraq.
“He led the Liberal Democrats to our party’s greatest electoral successes, yet he always remained modest about his huge achievements.
“Whenever I asked him for advice, he was unfailingly kind and wise.
“Most of all, I will never forget the pride and love with which he would talk about his own family, most especially his devotion to his son Donald.
“My heart goes out to his sister and brother and to Sarah and Donald at this tragic time.”
Mr Kennedy’s predecessor as Lib Dem leader, Lord Ashdown, said on Twitter: “Charles Kennedy. In a political age not overburdened with gaiety and good sense, he brought us wit, charm, judgement, principle and decency.”
Liberal Democrat leadership hopeful Tim Farron MP tweeted: “I am utterly heartbroken about the news of Charles’ passing. He was a colleague, friend and mentor. We’ve lost a giant today.”
Principal and vice chancellor of the University of Glasgow Professor Anton Muscatelli said: “Charles was a distinguished alumnus of the University of Glasgow and served two terms as Rector.
“He contributed an enormous amount, and was a friend to all who came into contact with him.
“The thoughts and prayers of all at the University of Glasgow are with Charles’ family at this dreadfully sad and tragic time.”
Sir Malcolm Bruce, deputy leader of the Liberal Democrats, said the death of Mr Kennedy, who was best man at his wedding, was unexpected.
“Most of the time he was fine, he was the old Charles. I don’t think we were expecting that,” he told Sky News.
“The thing people remember about Charles is he was able to bring such a light touch to politics.
“All of us really want people to reflect on what we’ve lost - a politician of his own type and quite unusual among other politicians.”