MP Tessa Munt is set to lose her parliamentary seat for the Wells constituency, which includes the Burnham-On-Sea area, at next year’s general election, according to an opinion poll.

A survey carried out in the so-called ‘battleground constituencies’ commissioned by Tory peer Lord Ashcroft, who hired pollsters to see how more than 1,000 people in each of 17 Tory-Lib Dem marginals across the country would vote.

Four key seats across the West country would swing from Lib Dem to Tory, despite the rise of UKIP nationally. They are Wells, Chippenham, Somerton & Frome and Mid-Dorset.

Lord Ashcroft’s polling suggests that, overall, a 3.5 per cent swing from the Lib Dems to the Tories would take place in the 17 marginals.

Lord Ashcroft said: “Ukip are not just a problem for the Tories. Those who voted Lib Dem at the last election were as likely to say they would switch to Ukip (13 per cent) as to say they would switch to Labour (13 per cent). A further 11 per cent said they intended to vote Conservative.”

“The party is literally losing votes right, left and centre. The Lib Dems are in their current position not because of anything Nick Clegg himself has done or not done, but because his party is in government with the Conservatives – a decision endorsed by the whole party through its exhaustive processes of internal democracy.”

“The centre-right coalition already has a left-wing alternative, led by Ed Miliband. Former Lib Dem voters who switched because they were dismayed that the party entered office with the Tories would only consider coming back if the party promised not to make the same decision in 2015, no matter what the election result.”

“Such a declaration is surely unthinkable, or ought to be for a party that wants to have any influence on the nation’s affairs,” he added.

“It would also look a bit rum to the voters: campaigning as the left-wing alternative to the left-wing alternative after five years in government with David Cameron, George Osborne, Theresa May, Iain Duncan Smith and Michael Gove would surely be a bit of a stretch,” he said.