Ukip have rejected as "nonsense" Tory criticism of the party using an Irish actor in a poster about the impact of immigration on British jobs.
The poster, published last week as the Eurosceptic party launched its campaign ahead of elections on May 22, features a builder in hi-viz and a hard hat begging on the street next to the slogans "EU policy at work" and "British workers are hit hard by unlimited cheap labour".
But it has emerged the man featured on the poster is Irish actor Dave O'Rourke, prompting Conservative MP Bob Neill to criticise the party.
He said: "I think it is pretty hypocritical of Ukip. They always like to say 'we are not part of the political establishment', they like to claim they are the party of ordinary people.
"They are using a trick most other parties stopped using long ago, because they get found out doing it.
"As far as I am aware, we always use genuine people in our adverts."
Ukip director of communications Patrick O'Flynn insisted in a statement the use of actors was "totally standard practice" in political campaigns - and pointed to the Tories' use of actors when William Hague ran the party.
He said: " The vast majority of people used in political poster campaigns are actors. It is totally standard practice.
"It is nonsense for the Conservative Party to try and depict this as anything out of the ordinary. For example, the people depicted in the Conservatives' "You paid the taxes..." campaign under William Hague were actors.
"So, Bob Neill needs to go and berate the Foreign Secretary if he really thinks there is anything wrong with this. Of course he won't because this is pure Tory party humbug.
"I would suggest that the only substantive difference between our poster campaign and Mr Hague's is that ours is proving popular and successful while his was followed by a landslide defeat."
The latest spat over Ukip's European election campaign emerged after leader N igel Farage admitted problems with the party's vetting procedures.
Ukip was yesterday forced to suspend a council candidate featured in its latest election broadcast for expressing "repellent" racist and anti-Islamic views on social media.
Mr Farage acknowledged "something went wrong" and said an internal investigation had been launched to find out how the party failed to spot the offensive Twitter messages posted by Andre Lampitt.
Mr Lampitt, wearing a builder's hard hat, appeared in a Ukip film shown to TV viewers, complaining that "since the lads from Eastern Europe" had arrived in the UK and undercut him, he had found it a "real struggle" to provide for his family.
But after being made aware of posts he previously made on Twitter, officials acted swiftly against Mr Lampitt - who is seeking to become a local councillor in Merton, south London.
Asked about Mr Lampitt's comments, Mr Farage said: "Repellent was the word we used and I will stick with that.
"We have got the European elections happening, we have also got local elections and we have got 2,234 candidates standing for Ukip... We have put in place a vetting procedure and something has gone wrong."
Pressed on whether he viewed Mr Lampitt's comments as racist, Mr Farage told BBC Breakfast: "I think they probably are, yes."
Mr Farage has previously pledged to root out individuals guilty of "real extremism and nastiness" in the party - which is coming under intense scrutiny ahead of the May 22 elections, where it is tipped to top the national poll.
He said: "We haven't got a monopoly on stupidity or on people saying repellent things, but obviously, given the criticism we faced last year, we have put measures in place and a mistake's happened, and I'm sorry about it."
Mr Lampitt's postings were reported to have included references to Islam as a "pathetic Satanic religion", a desire to create a website named Islamoutofuk.co.uk and a claim that "most Nigerians are generally bad people".
He also claimed, in a string of posts over several months, that Ed Miliband was "not a real Brit... He was only born here" and suggested the Labour leader was Polish.
In the party election broadcast, Mr Lampitt appears in a T-shirt bearing the logo of his home renovation, carpentry and electricals firm Kamina Kawena Services.
He told voters: "Since the lads from Eastern Europe were prepared to work for a lot less than anyone else I have found it a real struggle, it is getting hard to provide for my family."
Before the account was taken offline, he described himself on Twitter as: "Born British in Rhodesia and proud of heritage sad at how Britain is run."
Election nominations closed yesterday and Mr Farage acknowledged that the party was powerless to stop Mr Lampitt standing.
Merton Borough Council confirmed today in its published nominations Mr Lampitt would be on the ballot paper as the Ukip candidate in St Helier ward.
Mr Farage said: "Once the nominations are in, you can't stop people standing, so he will stand. But he is not the Ukip candidate."
Mr Farage defended his view that only his German wife Kirsten is capable of doing the job of being his secretary, claiming that the only way a British person could do the role would be if he divorced her and remarried.
Asked if a British worker could do the job, he said: "If I divorce her and marry somebody British, then yes."
Mr Farage said the job, for which Mrs Farage was "paid very modestly", involved dealing with " very confidential work and information, much of this happens at midnight or at 5am and happens in my office at home".
"Nobody else could do that job," he said.
Ukip rejected claims about another of its members, David Challice, after comments about women in the work place, polygamy and Greek and Turkish drivers were reported.
A spokesman said: "Ukip is not a party that believes in public debate and conversation being stifled by an obsession with political correctness. So the threshold for which the mere expression of opinion merits disciplinary action should be set high.
"That threshold was quite obviously breached in yesterday's furore but it is has certainly not been today. Indeed, there are quite legitimate public concerns about the interaction of the benefits system with men who have multiple wives and these have been widely aired in the media.
"Mr Challice's remarks about women in the workplace and his wife were intended as a joke and indeed were understood as such. He does not seriously believe women should not work. Given that his wife works in the same office as he does it would be curious if he did.
"The quote about Greek and Turkish drivers is not one originated by Mr Challice but is taken from a book by the noted cultural commentator Brian Sewell and indeed is attributed to Mr Sewell in the text."
Sky News reported Mr Challice, Ukip's administrative manager and a former regional party chairman, had suggested that "Cash-strapped Moslems" should have multiple wives; and suggested women should not go out to work.
The channel said in an advert Mr Challice placed in the Exeter Express and Echo he wrote: "There are differences that most sane people would recognise... W omen are home-makers... I have discussed this at length with Hilary [his w ife]. Since the snow came back all she's done is look through the window. If it gets any worse I'll have to let her back in again."