Nigel Farage has described the defection of Conservative candidate Mike Whitehead to Ukip as "another hammer blow to Tory pretensions in the north of England".
However, a Conservative Party spokesman dismissed Ukip's announcement as "cynical, misleading and utterly calculating to try and score political points".
A Conservative parliamentary candidate has defected to Ukip, the party has announced.
Mike Whitehead, an East Riding councillor standing for selection as MP for Hull West and Hessle, said he was "disgusted" with the behaviour of the ruling Tory group in East Yorkshire, and the "wilful refusal" of the national Conservative Party to intervene.
He also insisted the "secretive" council needed to be "opened up" and made more transparent".
Whitehead said he had been concerned about the behaviour of the controlling group of Tories since 2011, when seven Conservative councillors from Haltemprice and Howden resigned, claiming bullying and intimidation.
His parliamentary constituency is currently deemed a safe Labour territory, with former home secretary Alan Johnson defending a 5,700 majority from 2010, when the Conservatives finished third.
The Democratic presidential candidate may also have shown his cards on his choice of running mate.
The US president also shared a post on Twitter accusing Dr Anthony Fauci of misleading the public over hydroxychloroquine.
Fears over an impending second wave of coronavirus dominates Wednesday’s front pages.