For the first time, Cameron is less popular than his party

David Cameron has slipped behind his party in the popularity stakes for the first time, according to a new poll.

The survey by Lord Ashcroft saw 18% say they were more favourable to Cameron than the Conservative party, with 22% saying the opposite.

The finding is potentially hugely problematic for Cameron, who has struggled to maintain his authority over his parliamentary party even when polling clearly showed he was more popular than the Tories as a whole.

It is likely to encourage mutinous plot in the Tory party, where MPs are restless over gay marriage and the perceived detachment of the leadership.

But even now Cameron can content himself by comparing himself to Ed Miliband, who trails his party by a massive 28 points.

The prime minister is also considered better than Miliband at being prime minister, representing Britain in international negotiations and making the right decisions even when they are unpopular.

The only measure in which Miliband is considered superior is in "understanding ordinary people" – a category the Labour leader has long enjoyed a clear lead in.

The poll showed the Tories trailing Labour by ten points on 37% to 27%, with the Liberal Democrats on nine per cent and Ukip on 15%.

Worryingly for the Tories, voters seem to be moving further away from the party.

Eighteen per cent described themselves as moving towards it, while 55% said they were moving further away.

The figures for Labour were 30% and 39% respectively.