Three-party politics is now a reality, Lib Dem leader Charles Kennedy has claimed as his party made substantial gains including winning Newcastle.
Charles Kennedy says the "tide is going out for Labour"
Mr Kennedy hailed this "great result" as proof they could take votes from both Labour and Conservatives.
"We are likely to come second overall matching our highest ever share of the
vote. This is a party that really is going places," said Mr Kennedy.
He told the BBC's Today the party had won "new respect" over the Iraq war.
The party's greatest election trophy has been to take Newcastle council, ending 30 years of Labour control. The Lib Dems also gained Pendle from no overall control.
With only a few councils still to declare results, the party has so far won 132 extra councillors, it has also suffered reverses, losing control of Eastbourne, Cheltenham, Winchester and Norwich.
Mr Kennedy said the party's predicted national performance of beating Labour into third place - a BBC national projection based on key seats - meant the end of two party politics.
"This is really three-party politics in Britain now. The media has to wake up and start reporting politics in that way," said Mr Kennedy on BBC Radio 4's Today programme.
"The tide is going out for Labour," he said, and the Conservatives had failed to convince that they were "resurgent".
The BBC's national projection is for the Lib Dems to gain 29% of the vote - behind the Conservatives on 38%, but above Labour on 26%.
KEY LIB DEM GAINS AND LOSSES:
Gained - Newcastle
Gained - Pendle
Lost - Cheltenham
Lost - Eastbourne
Lost - Norwich
Lost - Winchester
Mr Kennedy said that the increased vote reflected the success of the party's policy of replacing the council tax with a local income tax and its promise to improve the environment.
But he rejected claims that the Lib Dems had only picked up protest votes over the Iraq conflict, and that those votes would disappear at the next general election.
"I prefer the history book to the crystal ball," he said, arguing that a year ago he had been warned that the Lib Dems would lose votes over their stance against the Iraq war.
"We have stuck to our principles and argued our case and I think we have won new respect and new-found support as a result."
Mr Kennedy said that the Lib Dems, rather than the Conservatives, were the only party that could challenge Labour in its traditional heartlands - as well as in the south.
And he said that the traditional pattern of the Liberal vote declining when Labour was doing badly had now been reversed.