The United Kingdom Independence Party has rejected as "nonsense" criticism of the party using an Irish actor in a poster about the impact of immigration on British jobs.
The poster was published last week as the party launched its campaign ahead of elections on 22 May.
It features a builder in hi-viz vest 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.
He 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 row over UKIP's European election campaign emerged after leader Nigel 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.