A new poll has suggested that the UK Independence Party is in line to take more seats than the Liberal Democrats in next month's European elections.

The YouGov survey in Monday's Telegraph indicated that UKIP is ahead of the Lib Dems among those who are "very likely" to vote.

According to this measure, the Conservatives are on 31 points, Labour is on 23 points, UKIP takes 18 points and the Lib Dems are on 15.

The results are less dramatic when all potential voters are taken into account, but still encouraging for UKIP.

Under this criteria the Tories are on 28 per cent, Labour 27, the Lib Dems 18 and UKIP 14, which would still double its seven per cent of five years ago.

But the expected low turnout in June, which YouGov estimates will be no higher than 39 per cent, makes a breakthrough to third place more likely.

With such a result, the party which advocates a complete withdrawal from the EU could expect to make sweeping gains in the European parliament.

Party leader Roger Knapman said that he expected UKIP's support to increase further before polling day.

"The poll results are in line with our expectations at this stage in the campaign, and we are confident that our share of the vote will increase further as our message gets across to voters," he said.

"Millions of British citizens believe as we do, that the UK would be better off outside the EU with merely a free trade agreement to replace our membership.

"UKIP’s success will send that message to the government in a way which will be impossible for them to ignore."

Blow

It would also be a blow to both the Lib Dems and the Tories who want to capitalise on the government's mid-term troubles.

With most UKIP voters coming from the Conservative ranks, Michael Howard could make few gains on the result achieved by William Hague in 1999.

"Even if it is right that the Tories are on 31 points, then that's a lead of eight points," a Labour official said in response to the poll.

"That's exactly the same lead they had five years ago. It shows they've made no progress at all."

And the Lib Dems said the poll actually indicated they could gain in June's elections.

Lord Rennard, the party's chief executive, said the increase in UKIP support was "entirely at the expense of the Labour and Conservative parties, who are both down five per cent compared to 1999 amongst those certain to vote".

"On all of the voting intentions questions, Lib Dems are up significantly compared to the last European elections and are also in a stronger position in relation to the general election," he added.

YouGov found that many of those questioned would vote differently in a general election, with 36 per cent backing the Conservatives, 33 per cent supporting Labour, the Lib Dems on 19 per cent and four per cent for UKIP.