The groups campaigning for a British exit from the European Union said today they were confident of winning the referendum vote, as the latest poll showed the rival camps neck-and-neck.

David Cameron has pledged that the EU referendum will happen before the end of 2017, but Government sources this week suggested that it could happen as early as next May.

Such an early date could pose problems for the groups campaigning for a ‘Brexit’ while allowing those preferring to remain an advantage, as it is widely perceived that David Cameron will campaign vigorously to stay.

Another issue is that while there is one group advocating staying, Britain Stronger in Europe, there are at least two vying for the right to be the official exit campaign.

Some Conservative MPs have called for Cabinet members to be allowed to campaign for an exit if that is their view, but they fear that the Government will maintain discipline in favour of the stay campaign.

But an early poll did not concern the Leave.EU campaign. Their co-chairman, Richard Tice, told Blasting News: "Whenever it comes, we will be ready and we will win. The clear trend of support is moving significantly our way as more and more people learn how the UK really can do so much better as an independent global trading nation rather than an EU subsidiary."

His hopes seemed to be borne out by the latest YouGov poll that showed 40 per cent intending to vote to remain, and the same number intending to vote to leave.

Both sides have been raising the stakes, even although the vote could be nearly two years away.

And in recent days other Governments, including China, have stated their support for the UK to remain.

The latest salvo in the debate came from the US Government. An aide to Barack Obama warned that if Britain leaves, the UK would not benefit from reduced tariffs as there is no Free Trade Agreement with the UK.

Richard Tice responded: “So we will be in the same position as we are currently! No problem.

“It suits the U.S. for the UK to be in the EU to enhance their own trading position, but we need to focus on what is right for the UK, not what is right for the US.”