Former sports minister Tony Banks is gravely ill and unlikely to recover from a serious stroke, his close friend David Mellor has said.
Tony Banks was taken ill on holiday in the US
The ex-Labour MP for West Ham, known as Lord Stratford, collapsed during lunch on Sanibel Island, Florida.
The peer, 62, was taken to Fort Myers hospital where doctors said the outlook was "bleak". Mr Mellor said he believed recovery was an "impossible" hope.
Lord Stratford became an MP in 1983 but did not stand in last year's election.
Mr Mellor, a former Conservative MP and fellow Chelsea fan, said: "I think he is in an irrecoverable position where effectively the stroke has destroyed his brain.
"Tony is a strong chap and his heart continues to beat manfully, but I fear that.....it is impossible to hope for any recovery, sadly."
The peer and his wife Sally had been staying with friends on Sanibel Island. His wife was not with him at the time he was taken ill, another friend said.
The BBC's political editor, Nick Robinson, said Lord Stratford was not on a life support machine, but was "apparently a victim of paralysis".
Our correspondent described the peer as "one of the great characters of Westminster" who cares passionately about politics.
'Man of the people'
Lord Stratford was known for his forthright views while an MP. His popularity with the public gave him a "man of the people" image.
His colourful language also got him into trouble at points during his Westminster career. He once described former Tory leader William Hague as a "foetus".
As an MP, his office was based in Stratford, east London, for 20 years, an area where he also lives.
He took the role of sports minister in Tony Blair's first administration but resigned in 1999 to concentrate on the unsuccessful bid to host the World Cup at Wembley.
From the backbenches he pursued his passion for animal welfare, contributing to the Hunting Bill debate.
'Man of conviction'
He sought to be selected as Labour's candidate for the 2003 London mayoral election, but was defeated by Nicky Gavron.
He caused surprise by taking the title Lord Stratford when made a working peer last year. But he called it a "nom de politics", saying he still expected to be largely known as Tony Banks.
The current sports minister, Richard Caborn, told BBC News the peer "left his mark in sport, football in particular", and is a "man of conviction who got his very serious point across", but is "never bitter and never personal".
Mayor of London Ken Livingstone also expressed his concern.
"This is a terrible shock and everybody's thoughts are with Tony's family at this time," he said.