UKIP’S record-breaking success in Clacton will change the face of British politics for years to come, experts have said.

Paul Whiteley, professor of politics at the University of Essex, believes the party’s rise will harm both the Conservatives and Labour.

He believes Ukip could win three or four seats at next year’s General Election, with the possibility of more representation in Essex.

Prof Whiteley spoke after Douglas Carswell, who defected from the Tories to Ukip, re-took Clacton at a by-election with nearly 60 per cent of the vote.

Gazette: Carswell's Comments

Prof Whiteley said: “It is one for the record books since the 44 per cent swing to Ukip has only been equalled once since the Second World War.

“In 2010, Ukip’s national vote was only three per cent and now it is about 14 or 15 per cent.”

Ukip is targeting eight seats in the House of Commons next May but Mr Whiteley believes four is a more realistic figure.

He said: “It is hard to call exact constituencies, but, of course, theywill be looking at seats where they already have representatives at county level.”

There are currently eight Ukip county councillors in areas including Basildon, Harwich, Braintree, Laindon, Rayleigh and Benfleet. Prof Whiteley said: “In General Elections you can’t concentrate on one area like you can at a by-election.

“Nigel Farage himself is fighting Thanet, which is in some respects similar to Clacton.”

The politics expert believes strong divisions between Ukip and the Conservatives on issues such as Europe and support for small business will see the two parties establish themselves as firm rivals.

He said: “David Cameron has got a progressive agenda and many Ukip supporters don’t like that. Ukip is not going to be a party that is going to fizzle out.”

In the short term, more votes for Ukip could make another coalition Government more likely next year.

Prof Whiteley said: “Forecasting models vary between a bare Labour majority, a Labour/Lib Dem coalition or the Conservatives and the Lib Dems again.

“It is so close that any of these variations could occur if the balance tips one way or the other.

“The Clacton result has already tipped Labour five points ahead in the polls compared to a few days ago.”