LONDON (Reuters) – More than 50 per cent of Britons want to leave the European Union while 47 per cent would like to remain in the bloc, an opinion poll conducted by pollster Survation on behalf of the ‘out’ campaign said on Friday.

Survation said the poll was the first since Prime Minister David Cameron’s specific demands for changes to Britain’s relationship with the 28-member bloc were widely reported before he sent an official letter to Brussels earlier this week.

Cameron wants Britain to stay in a reformed European Union in a referendum due by the end of 2017, but has warned the bloc that if his demands fall on a “deaf ear”, he could lobby to leave.

Survation, which conducted the poll on behalf of ‘out’ campaign Leave.EU, said 53 per cent of the 2,007 people polled between Nov. 9-11 wanted to leave the European Union against 47 to remain. The pollster excluded the undecided.

It also said 22 percent said they believed that Cameron would likely get a good deal and most wanted him to concentrate on restricting benefits to EU migrants.

Cameron has set out four areas where he wants to see change; welfare payments to EU migrants, safeguards for countries outside the 19 member euro zone, Britain to be excluded from the principle of “ever closer union” and the establishment of greater competitiveness.