TORY MP Douglas Carswell quit his party yesterday and joined Ukip.

The Clacton MP said he will step down from Parliament to force a by-election and run again as a Ukip candidate.

But a leading anti-racism campaigner said the by-election was a “high-risk” strategy for Ukip leader Nigel Farage.

Gerry Gable of Searchlight magazine said the Essex town was part of a “white” belt of right-wing constituencies.

“If they were to fail in such a place it would do Ukip and he as its leader a huge amount of damage in the run-up to next year's general election,” he said.

“The good thing is the trade union movement is active through its local trades councils, which Trade Union Friends of Searchlight has been very much engaged with, supporting existing ones or renewing some dormant ones.”

And Mr Carswell’s ambitions were dealt a further blow when existing Ukip candidate Roger Lord went online to say he had “no intention” of stepping down.

“As far as I’m concerned I’m carrying on,” he told Buzzfeed.