The Conservatives' Wakefield candidate has sparked controversy after suggesting the far-right British National party (BNP) is gaining most of its support from ex-Labour voters.
Alex Story told a hustings event in Wakefield cathedral this lunchtime that Tory supporters would not be voting for the BNP on May 6th.
"The BNP is a function of the Labour party's failings on immigration," he said.
"I can assure you they will not be Conservative voters. Labour voters will tell me 'I used to work down pit and I will vote BNP'. Take a walk down Peacock and speak to people."
Incumbent Labour candidate Mary Creagh attracted applause for her dismissal of Mr Story's claim during the hustings. She cited socialist supporters of the struggle against General Franco in the Spanish civil war as an example of Labour's long history of fighting far-right politics.
"Alex said the BNP is an offshoot of Labour. I take absolutely enormous exception to that," she told politics.co.uk after the event.
"We have a long tradition in the Labour movement of fighting against all forms of racism and xenophonbia. And I'm not going to sit in Wakefield cathedral and be told my party is somehow part of the BNP."
Mr Story told politics.co.uk: "The premise of what I said was a dig at the Labour party for the situation we're now in.
"The Labour party believed or said they represented a certain group of people. If you speak to them now they vote BNP."
He argued Ukip's relationship with the Conservatives was comparable to the BNP's relationship with Labour.
"The BNP vote is in fact an ex-Labour vote that is disenfranchised from the Labour party and is in disagreement with the Labour party on the immigration issue," Mr Story insisted.
"If you don't believe me please go with people who canvas on our estates and you will see what I mean."
Ms Creagh conceded a "communication gap" had developed between voters' perceptions of the issue and the government's policies.
"We have no problem with people who want to work coming over here," she added.
"But we need to be fair and make sure they're not displacing our own people out of jobs."
Labour has held Wakefield since the 1930s but local Tories say they are confident of taking the seat in 2010.
Their target, Ms Creagh, has only served one parliament as the seat's MP. She is defending a 5,134 majority which has been boosted to around 7,000 by boundary changes. Mr Story is her main challenger.