Nigel Farage says Prime Minister David Cameron has come out "the least scathed" of the major party leaders following the local and European elections.
Speaking at a press conference, Mr Farage said a bigger test for the Conservatives would be the Newark by-election at the end of next week.
"Ukip, with the wind behind it, has got momentum," but said the "massive" Tory majority in the constituency meant the challenge was akin to "being asked to climb Everest".
"If we do that then I suspect Mr Cameron will start to feel some of the pressure," the Ukip leader said.
Today EU leaders voted to back Jean-Claude Juncker as new president of the very powerful EU commission, which looks like business as usual.
In Essex the potential damage Ukip could do to Miliband's Downing Street elections is clear. He is there listening to voter's concerns.
The EU parliament is about to welcome the most Eurosceptic and right-wing intake in its history.