UKIP is on course to win the Rochester by-election, according to the latest opinion poll.
The ComRes survey found UKIP well ahead of the Conservatives among voters in Rochester before next month’s by-election with four in 10 of those who voted for Cameron’s party in 2010 now planning to switch.
The poll put UKIP on 43 percent, the Conservatives on 30 percent and the Labour Party on 21 percent.
The election was triggered by the decision of Mark Reckless to defect to UKIP from the Conservative Party.
Two weeks ago UKIP won its first elected seat in parliament when another Conservative defector Douglas Carswell won a landslide victory in the seaside town of Clacton.
Nationwide polls have shown support for UKIP, which backs tighter immigration controls along with an EU exit, reaching a record high of 25 percent.
Its rise increases the likelihood of another coalition government, threatening Cameron’s re-election drive by splitting the right-wing vote, but also posing a challenge to Labour.