UKIP has accused the Conservative party of running a "morally reprehensible" smear campaign by trawling through potential councillors' Twitter and Facebook posts.
The party - which is investigating a handful of candidates over links to groups such as the BNP and alleged racist and homophobic comments - said it did not condone "unpalatable views".
A spokesman insisted it would not bow to a "political lynch mob".
The row came as emails leaked to the Observer revealed that one of the party's MEPs is concerned about excessive "political correctness" among new recruits.
More top news
In an interview with ITV News, Antonio became the first England player to speak out about the allegations against Sam Allardyce.
The Labour leader needs to start reaching out to Conservative and Ukip voters if he wants the keys to Downing Street.
Sam Allardyce's former assistant Phil Brown says the end of his brief reign as England boss is like a bereavement.