The Ukip leader endured what was one of the toughest weeks of his political career and yet support for his party was sustained. Mr Farage could even come first in the elections in less than four weeks.

A series of Ukip posters that warned “26 million people are looking for work – and whose jobs are they after?” and “British workers are hit hard by unlimited cheap labour” were condemned by opponents but a YouGov poll showed that the majority of voters – 57 per cent – believe the ads were a “hard-hitting reflection of reality”, and 59 per cent said they were not racist.

With the European poll Labour’s to lose, Ed Miliband will launch his party’s campaign this week when he will be forced to take on directly the challenge from Ukip. Mr Farage is targeting Labour voters by touring northern England. If Ukip comes first, Mr Miliband is certain to face questions over his campaign for Downing Street in a year’s time.

On a visit to the West Midlands yesterday, Mr Farage insisted that the three main political parties were trying to “smear” his MEP candidates and that they were running scared.

However, there were fresh claims about one of Ukip’s candidates when it emerged that a former Conservative council leader – who resigned after a scandal over expenses – is to stand for the party at the next general election.

David Parsons, who previously led Leicestershire County Council, denied any wrongdoing but agreed in February this year to pay back nearly £2,400 relating to 26 car journeys that a council report concluded were “not sufficiently connected with his role” and two others that were too short given the waiting time for the driver. Details of the journeys were not given.

Mr Parsons, who left the Conservative Party in 2012, is to stand for the North West Leicestershire seat in the election next year. He told the Leicester Mercury that he had “witnessed first-hand how in recent years the local Conservative Party has wilfully disregarded the interests of local people”.

“At a time when so many of us are struggling to make ends meet, we are left to the whims and fancies of a Tory/Liberal coalition, both locally and nationally,” he added. “I believe Ukip is now the only political party which truly represents the hopes and aspirations of the people in our constituency.”

Mr Parsons said the seat was one of Ukip’s top 25 targets and promised to focus on a “positive message” rather than “the negative stuff churned out by the other, old parties”.

The sitting Conservative MP, Andrew Bridgen, said that when he heard who was standing for Ukip he “couldn’t stop laughing”. Neither Ukip nor Mr Parsons would respond to requests for comment yesterday.

In the European elections, the Olympic gold-medal-winning rower James Cracknell is standing as a Conservative candidate for the South-west. Tory insiders predict that, if he is not elected an MEP on 22 May, he will be put forward to fight for a winnable Westminster seat for the Tories.

In an interview with The Independent on Sunday, Mr Cracknell did not rule this out, but added: “There’s a job to do in Brussels. I haven’t gone the traditional route into politics. Whatever route I take, it’s all going to be new to me. Will the frustration be too much or drive me mad? I genuinely don’t know.

“All I know is that in the next five years we will see a massive change in Europe and I want to be there to make sure Britain and Europe get the best deal. We’re better off being in Europe if it’s done the right way and at the moment it’s not.”

Mr Cracknell questioned Mr Farage’s commitment to his job, saying: “In spite of all his expense claims, Farage just does not turn up. Ukip may be getting the profile over here, but you’ve got to deliver on the things that make a difference, and Ukip won’t be able to do that.”

Meanwhile, an anti-nuclear campaigner has been barred from running in the European elections after a bureaucratic error caused him to miss an application deadline.

Richard Cottrell, who has fought against the development of a nuclear power station at Hinkley Point, Somerset, had intended to stand alongside North Somerset councillor Geoff Coombs as the newly formed Campaign West Independent party.

The Electoral Commission wrote to the party stating that the closing date for applications was 23 April and did not inform them of changes published online that moved the deadline forward by a day. Mr Cottrell is now seeking a judicial review.

The former MEP for Bristol accused the commission of “lacking a duty of care to all the candidates in the election”.

He said: “This year there has been huge confusion. They should have notified all parties of all or any changes in procedure and this was not the case.”

The change of application deadline took place due to a miscalculation of the differing bank holidays held in the South-west and Gibraltar, which was ceded with the constituency in 2004.

Mr Cottrell said that the inclusion of Gibraltar in the South-west was the direct cause of his exclusion and that the island should be able to elect its own MP, as is routine in the Falklands and French overseas dependencies.