Scotland's First Minister, Mr Donald Dewar (67), is seriously ill and unconscious on a life-support machine.
Mr Dewar, who underwent heart by-pass surgery this summer, fell to the ground yesterday afternoon as he was leaving his official residence. "He is on a life support machine and is critically ill. He will be kept under observation overnight," Mr David Whitton, his personal adviser, said at Edinburgh's Western Infirmary.
He was leaving Bute House in Edinburgh when he slipped. According to official sources he brushed off the incident saying he was fine. Later in the day he is said to have felt ill and was taken to hospital.
A brain scan revealed internal bleeding and an ambulance took him to the neurological unit at the Western General hospital in the city.
The rapid decline in Mr Dewar's health over a matter of hours is thought to be linked to his heart surgery three months ago. It is believed his prescribed medication thins the blood and this has contributed to his condition.
Since returning to work a matter of weeks ago colleagues have privately spoken of his tired and weak appearance.
Mr Dewar is a self-confessed workaholic more comfortable carrying out his duties than resting at home.
The First Minister has been dubbed the "Father of the Nation" as he steered the legislation through Westminster that saw the creation of Scotland's devolved parliament.
It gave Scotland home rule and was a key plank of British Prime Minister Blair's programme of constitutional reform.
Mr Whitton said Mr Blair had been in touch by telephone, and added that his Downing Street residence in London was being kept informed of Mr Dewar's condition.
"It won't surprise you to learn that Mr Dewar has many friends in the cabinet, many of whom have been on the phone to find out how he is," said Mr Whitton.
He said Mr Dewar's children, a daughter who lives in Brussels and a son in London, had been told and were travelling to Scotland.
Mr Dewar, a former lawyer, is head of the Scottish wing of Britain's ruling Labour Party.
He became Scotland's First Minister last May, but only after hammering out a coalition deal with the minority Liberal Democrats when the Scottish electorate denied Labour an overall majority in their new parliament.
He had been Scottish Secretary in the British cabinet before the elections last May.
Mr Blair described him as the driving force behind the idea that giving Scots more of a say in their affairs would kill off nationalist demands for full independence.
In his absence the Deputy First Minister, Mr Jim Wallace, assumes Mr Dewar's responsibilities.