A jubilant Nigel Farage has insisted Ukip will be "serious players" at the general election after the party landed major blows on the Tories and Labour in local polls.
Mr Farage predicted his party could hoover up 200 extra council seats by the end of the day - and said European election results due Monday could be even better.
Pointing to significant wins in Essex and areas such as Rotherham, he suggested the "Ukip fox is in the Westminster hen house".
"There are areas of the country where now we have got an imprint in local government," he said. "Under the first-past-the-post system we are serious players."
The comments came after a disappointing night for Labour, where the party failed to secure control of councils in spots such as Thurrock, considered crucial for a general election victory, although results in London were more impressive.
Shadow Foreign Secretary Douglas Alexander said the country appeared to have entered a period of "four-party politics".
The Conservatives were set for heavy losses, with Education Secretary Michael Gove admitting voters had turned to Ukip to send a "very clear message", and the Liberal Democrats also suffered.
With over a third of councils having declared, Ukip had gained nearly a hundred seats - already exceeding expectations of around 80 wins.
They included 11 in Basildon to ensure it went from Tory to no overall control, and five in Thurrock to rob Labour of overall control.
In the north, Ukip showed it could pose a threat in the traditional strongholds of Ed Miliband's party, taking 10 of the 21 council seats up for election in Rotherham.
So far Labour has boosted its councillor numbers by around 70, the Tories have lost some 110 and the Lib Dems more than 60.
Mr Farage said he believed many people would have stuck by long-standing council candidates representing the three main parties, but voted Ukip in European elections.
"Looking at the average vote share across the country and without wanting to count any chickens before they are hatched, it looks pretty good," he added.