The rise of the right-wing: UK Independence Party campaigning to win first seat at Westminster

A small seaside town on the English coast is in the centre of a political battle that could this week see the populist UK Independence Party (UKIP) win its first seat at Westminster.

The residents of Clacton-on-Sea in Essex will vote in a by-election triggered by Conservative MP Douglas Carswell's defection to UKIP.

Mr Carswell is one of two Tory MPs to jump ship - meaning British prime minister David Cameron can no longer write UKIP off as a party full of "fruitcakes, loonies and closet racists".

Clacton has a higher than average rate of unemployment and a high number of pensioners, and Tim Bale, Professor of Politics at Queen Mary University London, says that makes it a "particular type of constituency where you'd expect UKIP to do well".

"It's not the land that time forgot", said Professor Bale, but "it's got a lot of what I sometimes refer to as left-behind voters, voters for whom globalisation has not necessarily been good news".

UKIP campaigns for tight curbs on immigration, but Mr Carswell rejects the suggestion that the party is anti-immigrant.

"We are not anti-immigrant", he said, "we are against uncontrolled immigration."

But that is not how many of his supporters see it.

Almost everyone we speak to in Clacton-on-Sea appears to favour some kind of blanket ban on immigration.

Many say they will definitely vote UKIP or are strongly considering it for that reason.

"Well I'm thinking of UKIP," said one middle-aged woman, who said she would traditionally vote Labour, "hopefully to get Great Britain back to Great Britain, because it's obviously not Great Britain anymore, we've got everyone here."

Another older man is even more blunt. He tells me he will be voting UKIP because, "I like their policies of getting rid of all our immigrants."

"They’re coming over here and we're keeping them," he said, "we don't send them back even if they're illegal."

UKIP running on anti-immigration, anti-establishment platform

A young man who said he wouldn't vote because he never did, said he still thought it would be good thing if UKIP got in.

"It might stop a lot of foreigners, and I don't mean any disrespect by that," he said, "but we've got too many of them now and we're losing the English inheritance."

UKIP's message is also strongly anti-establishment, and that is hitting home with many voters who have become disillusioned with the mainstream political parties.

Professor Bale said "ordinary people feel like they've never really been asked about immigration for example, they've never been asked about Europe, they've never been asked about their opinions on a whole series of policies which this government and governments before have pushed through."

"People in this country have had enough of a remote unaccountable elite of arrogant politicians in Westminster telling us how to live our lives," Mr Carswell said. "We’ve had enough of it."

The party, whose charismatic leader Nigel Farage, somewhat ironically, is a Member of the European Parliament, advocates Britain leaving the European Union.

"Imagine what it would be like if in Australia most of the key decisions that affected your life were made by an unelected, unaccountable commission in Singapore", Douglas Carswell said. "You would object."

Mr Carswell looks set to win back his seat for UKIP, and the Conservatives are taking notice.

Cameron says a vote for UKIP is 'really a vote for Labour'

At the Conservative Party’s annual conference in Birmingham last week, David Cameron appealed to voters to stick with his party at next year's general election.

"If you vote UKIP that really is a vote for Labour," the prime minister told delegates. "And here's a thought for you... you could go to bed with Nigel Farage and wake up with [Labour leader] Ed Miliband," he said.

To guffaws from the audience a smiling Mr Cameron then delivered the punch line: "I don't know about you, but not one bit of that works for me."

It is not just the Conservatives who have to worry.

Labour could see working-class supporters switch allegiance next May.

Another by-election also being held next week in northern England is being seen as a test of the likelihood of that happening.

The election in Heywood and Middleton was triggered by the death of the sitting Labour MP.

Labour should retain the seat, but any significant swing to UKIP will raise alarm bells.

"This is really kind of payback time for the political class," Professor Bale said.

Mr Cameron will be hoping that is not the case, not least because October 9, the day one of his former MPs could win a seat for a rival party, coincidentally is also his birthday.