Half of Britons support a second vote on whether to leave the European Union and a third think will be worse off financially outside the world's largest trading bloc, according to a new opinion poll.

The poll, published in the Mail on Sunday newspaper, found 50 percent of people support another vote on the final terms of Britain's exit deal, 34 percent rejected another referendum and 16 percent said they did not know.

The newspaper said it was the first major opinion poll since last week's media reports that Britain is preparing to pay about €50 billion ($59 billion) to help to pave the way for talks on a future trade pact with the EU.