Mike Whitehead was standing against Labour's Alan Johnson in the Hull West and Hessle constituency in Yorkshire . Nigel Farage today insisted the Tories had suffered a 'hammer blow' after a former parliamentary candidate defected to Ukip - only for it later to emerge that he had already been sacked from the party last week. Mike Whitehead, who was standing against Labour's Alan Johnson for the Tories in Hull, claimed he was joining Ukip after becoming 'disgusted' at the behaviour of the ruling Conservative group in his area. But the Tories this morning revealed they had already dropped Mr Whitehead as their candidate  after he revealed he was planning to stand as an independent against a Tory councillor. A spokesman for the Tories said: 'This man is not our candidate for Hull West and Hessle. He was sacked last week. 'We wrote to him last week to say that his position was untenable and could not stand for us at the General Election. We were already selecting a new candidate for this constituency. This is typical Ukip – cynical, misleading and utterly calculating to try and score political points.' Mr Whitehead, speaking on BBC 5 Live this morning, confirmed he was sacked last week. He said: 'I got an email on Wednesday evening to say that if I didn't stand aside from my intentions to stand in the local elections, they would remove my candidacy in West Hull and Hessle. 'I said I wasn't prepared to do that and so as I wouldn't give them that guarantee they terminated my candidacy in West Hull & Hessle.' Mr Whitehead said he had been increasingly worried about the behaviour of the controlling group of Tories in East Yorkshire since 2011, when seven Conservative councillors from Haltemprice and Howden resigned, citing bullying and intimidation. He added: 'In my opinion, the behaviour of the ruling group has only gotten worse since then.' Mr Whitehead said he could no longer carry on 'in good conscience'. Scroll down for video . Responding to the news, Mr Farage said: 'I am delighted to be welcoming Mike to the party at this exciting time. 'His move to Ukip just underlines that today the real party of opposition to Labour in the north is Ukip. It is another hammer blow to Tory pretensions in the north of England'. Ukip Yorkshire and Humber MEP Mike Hookem said: 'Mike has shown himself to be a man of principle in standing up for what he believes in and I am looking forward to working with him in the near future.' Nigel Farage claimed the scalp was 'another hammer blow' for David Cameron, just a month before the general election . Fellow Ukip MEP Jane Collins said: 'Both Mike and his colleague Mick Burchill, who defected earlier this week will be standing for Ukip in the local elections. 'I think they will both be a great addition to the Ukip team in this area and I am also looking forward to working with them closely.' Hull West and Hessle is safe Labour territory - former home secretary Alan Johnson is defending a 5,700 majority from the 2010 general election when the Conservatives finished third.
Mike Whitehead was standing for the Tories in Hull West and Hessle .
He resigned as a councillor last week in 'disgust' at local party politics .
The Tories claim Mr Whitehead was sacked as a candidate last week .
But Nigel Farage this morning insisted it was a 'hammer blow' for Cameron .