British Prime Minister David Cameron's flagship policy of reforming the country's relationship with the European Union before holding an in/out referendum has the support of the majority of British companies, a poll suggested on Wednesday.

The quarterly survey of nearly 4,000 companies for the British Chambers of Commerce, a business lobby group, found 77 percent were in favor of giving voters their first referendum on EU membership since a plebiscite in 1975.

The BCC poll found just over 50 percent of the companies thought withdrawal would be bad for business, compared with 20 percent who thought it would be positive.

Cameron's promise in January of reaching a new settlement with Brussels before an in/out vote by the end of 2017 alarmed some of Britain's biggest allies and fuelled talk of London ending its 40-year membership in the bloc.

The economic impact of pulling out has divided business leaders, politicians and commentators and strained Cameron's relations with his Conservative Party's pro-EU coalition partners, the Liberal Democrats.

Cameron hopes his referendum pledge - currently opposed by the Liberal Democrats and the opposition Labour Party - will give him the edge at the next election in 2015.

Sixty percent of those surveyed thought Cameron's preferred option - staying inside the bloc on new terms - would be good for business, 11 percent thought it would be bad and the rest were uncertain.

The BCC surveyed 3,906 businesses in May and June. Full results are online: http://www.britishchambers.org.uk/.

Reuters