Poll shows Britain's UKIP to win parliamentary seat after lawmaker defection

LONDON (Reuters) - Britain's anti-EU UK Independence Party (UKIP) will win its first directly elected parliamentary seat after the defection of a lawmaker from Prime Minister David Cameron's Conservative party last week, an opinion poll on Sunday showed. Last week Douglas Carswell switched allegiance to UKIP, saying he no longer believed Cameron wanted major reforms to Britain's ties with the European Union. Carswell, 43, triggered a fresh election in his southern England constituency by resigning on Thursday, saying he wanted to be re-elected under the UKIP banner to validate his switch. A poll of 700 residents in the constituency forecast a landslide victory for UKIP and Carswell over the Conservatives. The poll by Survation, published in the Mail on Sunday, put UKIP on 64 percent, 44 percentage points ahead of the Conservatives. UKIP's popularity has surged since 2010 on the back of its campaign for an immediate withdrawal from the EU and an end to what it calls "open door" immigration. UKIP has continued to siphon support away from Cameron's party, threatening their chances of re-election next May, despite the Conservatives promising to negotiate reforms and hold a referendum on Britain's EU membership if they win the national election. Sunday's poll represents a huge swing towards UKIP from the Conservatives, for whom Carswell won the seat in the 2010 general election with a majority of more than 12,000. (Reporting by William James; Editing by Rosalind Russell)