Roger Lord, who had been the Ukip general election candidate for Clacton until Douglas Carswell jumped ship yesterday, has called the Tory defector an "idiot".
"If somebody pushes me, I'm going to push back," he said. "Has he [Carswell] got a membership card? I'm not sure he's officially a member yet."
Mr Lord told ITV News Political Correspondent Libby Wiener that Mr Carswell "could have said sorry, but he hasn't got the guts to do it".
More top news
Scientists believe they have invented an ice cream that will melt slower in the sun.
There were shocks, tears and skimpy outfits at the star-studded MTV Video Music Awards in LA.
Ferry services from Calais have resumed in the wake of Sunday's blockade but passengers have been warned they face delays.