The Liberal Democrats have snatched one of Labour's safest seats with a victory in a key north London by-election.
Kennedy: The government has got to listen
Sarah Teather won the Brent East poll by more than 1,100 votes, overturning a 13,047 majority and marking Labour's first loss of a Commons seat in a by-election for 15 years.
London MEP Robert Evans received 7,040 votes compared with Ms Teather's 8,158, while the Conservative candidate Uma Fernandes was beaten into third place with 3,368 votes.
The 29% swing from Labour to the Liberal Democrats is the largest for almost a decade, and is being described by commentators as one of the most stunning turnarounds in British electoral history.
However, with a turnout of 36.4%, senior Labour figures say many of the party's supporters simply did not vote.
LABOUR'S VOTE SHARE FALLS
Labour vote share dropped by 29.5% compared with the general election
The Lib Dem share rose by 28.6%
Tories dropped by 2%
Turnout was low on 36%
Swing was 29% from Labour to Lib Dems
The by-election took place on Thursday after Labour MP Paul Daisley died of cancer in June, aged just 45.
Lib Dem leader Charles Kennedy said the result was "a big boost" for the party ahead of its annual conference in Brighton next week.
"We have shown that there is no such thing as a no-go area for the Liberal Democrats," he said.
"In Britain's most diverse community, we have shown that we can speak for every section of society and the Liberal Democrat message is one they want to hear and support."
The party will now have 54 MPs in Westminster, with 29-year-old Ms Teather making the transition from being a councillor in Islington to become the youngest member of the Commons.
Commentators are linking the Labour defeat with Tony Blair's decision to go to war with Iraq, and anger among the party's traditional voters over the involvement of the private sector in public services.
"It's led to an awful sense of doubt both about Tony Blair personally and about this administration and I think that's going to be the difficulty for the government," Mr Kennedy told BBC Radio 4's Today.
For the Lib Dems, the result is being seen as a huge boost, proving they win by-elections not only against the Tories, but also against Labour.
Ms Teather said she was "absolutely elated" by the result, which came in at about 0230 BST on Friday, adding that both Labour and the Conservatives should take careful note of the outcome.
"Tony Blair, I hope that you are listening tonight. The people of Brent have spoken for the people of Britain," she said.
"They want you to listen. They want you to
RESULT IN FULL
Sarah Teather (Lib Dem) 8,158
Robert Evans (Labour) 7,040
Uma Fernandes (Conservative) 3,368
Noel Lynch (Green) 638
Brian Butterworth (Socialist Alliance) 361
Khidori Fawzi Ibrahim (Public Services Not War) 219
Winston McKenzie (Independent) 197
Kelly McBride (Independent) 189
Harold Immanuel (Independent Labour) 188
Brian Hall (UK Independence Party) 140
Iris Cremer (Socialist Labour Party) 111
Neil Walsh (Independent) 101
Alan Howling Lord Hope (Monster Raving Loony Party) 59
Aaron Barschack (No description) 37
Jiten Bardwaj (No description) 35
Rainbow George Weiss (WWW.XAT.ORG) 11
"But there is no comfort in this result tonight for the Conservative Party.
They are irrelevant to constituencies like this," she added.
"The tide may be turning against Tony Blair and New Labour, but the tide
remains far out for the Conservatives in this country. "
Labour said it was disappointed with the poll.
Chairman Ian McCartney said: "The backdrop of the controversy surrounding the Iraqi conflict, in its many forms, made this the most difficult by-election Labour has fought in the last 20 years.
"A disproportionate number of Labour voters staying at home was also a key feature."
Mr Evans, the Labour candidate, was optimistic despite defeat.
"I think if we're honest some of the results of Labour investment in health,
in education, in the fight against crime haven't yet filtered through to
voters," he said.
"Clearly we've had a by-election - people have exercised the right to perhaps vote differently (from how) they might do in a general election and so obviously we're very disappointed.
"But we'll bounce back."
Lessons to learn
In the 2001 general election Mr Daisley managed to secure a majority of 13,047 with 63.21% of the vote.
He took over the seat from Ken Livingstone, who became London's mayor.
Then the Tories came second with 18.21% of votes cast, while the Liberal Democrats picked up 10.57%.
The Conservatives said they would examine the campaign and learn from it.
Conservative chairman Theresa May said: "I'm disappointed for Uma Fernandes, because I think she was an extremely good candidate.
"Of course parties don't want to come third in elections but our vote held up, contrary to predictions that it was going to collapse.
"We will look at the campaign and learn the lessons from the campaign but we are a party that is on course for the general election."