Ukip could hold balance of power says Farage as his first MP enters Commons

On a bruising night for the three main parties, Tory defector Douglas Carswell cruised to victory in Clacton, where he had stood down as MP to fight the seat as a Ukip candidate.

And in the traditional Labour stronghold of Heywood and Middleton, Ukip came within just 617 votes of overturning a 6,000 majority.

Mr Farage said the results had “shaken up” the entire British political system and predicted that Ukip would take its second seat in Rochester and Strood, where another Tory defector - Mark Reckless - has also stood down to force a by-election.

“The whole of British politics has been shaken up in a way that the complacent Westminster class could never even have contemplated,” Mr Farage told BBC News.

“Something big is happening here. People want change. They have had enough of career politicians in three parties who don’t even understand the problems they face in their everyday lives. People want real change.

“We’ve got a chance here in a general election next year that is likely to be very tight, in an election in which no one party is likely to have a majority - if Ukip can keep this momentum going, we could find ourselves next May in a position where we hold the balance of power.”

In Clacton, Mr Carswell won with a majority of 12,404 over the Tory candidate Giles Watling, taking nearly 60% of the vote, increasing both his majority and vote share from those he achieved as a Tory in 2010.

On a 51.2% turnout his 21,113 votes saw him comfortably defeat Mr Watling, on 8,709 votes, with Labour in third place and the Greens pushing the Liberal Democrats down to fifth - losing their deposit.

In Heywood and Middleton Liz McInnes held the seat for Labour in the contest following former MP Jim Dobbin’s death.

On a turnout of just 36%, Ms McInnes won with 11,633 votes, a 40.9% share, defeating Ukip’s John Bickley on 11,016, a 38.7% share.

Tory Party chairman Grant Shapps warned that the loss of Conservative votes to Ukip threatened to hand power to Labour at the general election in May, putting paid to David Cameron’s plans for a referendum on Britain’s membership of the EU.

“This is an alarm clock moment. The mathematical outcome of the next election is either Ed Miliband in Downing Street or David Cameron,” he told the BBC Radio 4 Today programme.

“If what happened last night were repeated in 210 days time in the general election and you saw Conservative seats become Ukip seats what you will have is Ed Miliband in government. That means you don’t get that in/out referendum.”

He described Mr Farage as “a bit like Nick Clegg after a few pints”, adding: “We simply don’t know what these guys stand for.”

However the Ukip leader said the result in Heywood and Middleton showed that his party was now the real alternative to Labour in northern England.

“In the north of England, in all those cities, the only challenger to Labour is Ukip and if you vote Conservative you will get Labour in all of those northern constituencies,” he said.

Labour’s campaign co-ordinator, shadow foreign secretary Douglas Alexander, said the party had actually increased its share of the vote in Heywood and Middleton, despite seeing its majority slashed.

“The reason the Ukip number moved up was not because there was a collapse in Labour’s share of the vote, but there was a complete collapse in support for the Liberal Democrats and indeed the Conservatives,” he told BBC News.

He acknowledged however that the result showed the party had a lot of work to do in seats right across the country.

“If the central driver of support for Ukip is an alienation and anger about how politics has been done then the challenge for the Labour Party is not simply to respond with the traditional tools of politics,” he said.

“We have got to defeat them conversation by conversation, doorstep by doorstep, street by street, community by community. We need to tackle the alienation that lies at the root of the anger that so many voters feel.”

Nevertheless the closeness of the result threatened to open up fresh questions about Mr Miliband’s leadership.

Backbencher John Mann said: “The real issue is why so many Labour voters are not bothering to vote. The mantra of ‘must work harder’ is not sufficient.

“If Ed Miliband does not broaden the Labour coalition to better include working class opinion then we cannot win a majority government.

“Ed Miliband does a lot of listening. Now he needs to do a bit more hearing.”

Labour MP Frank Field said: “If last night’s vote heralds the start of Ukip’s serious assault into Labour’s neglected core vote, all bets are off for safer, let alone marginal seats at the next election.”

Mr Miliband said Labour would seek to “reach out” to voters who had turned away from the party.

“What we saw last night was a Tory Party losing in their own backyard in Clacton and in retreat on what used to be their front line in the North West,” he told reporters as he left his London home.

“But there won’t be a shred of complacency from us as we reach out to all of those voters who didn’t vote Labour and those who didn’t vote at all.”

Mr Farage, meanwhile, hinted that there are more defections in the pipeline, suggesting that they could come from Labour as well as the Conservatives.

“I have had these conversations with backbench Conservatives. I have had these conversations with some backbench Labour MPs as well,” he said on an LBC radio phone-in.

“I would be surprised if there weren’t, over the course of next few months, more defections. Do not forget what happened yesterday in Heywood and Middleton was extremely significant.”

Speaking in Heywood, Ukip deputy leader Paul Nuttall said: “For us up here in the North of England, we’ve proven we are the only opposition to the Labour Party.

“John (Bickley) came literally within 600 votes of taking this seat. Labour’s majority has been cut from 6,000.

“They couldn’t get their vote out. Their campaign was flat.”

He added: “In the North of England, if you vote Conservative, you get Labour. That now is perfectly clear.”

Mr Nuttall, who was speaking at a press conference with Ukip candidate Mr Bickley, criticised Labour for calling the by-election too soon after the death of former MP Jim Dobbin, saying the normal procedure was to wait until after a funeral.

He predicted that Ukip would have won if the vote had been later, even by a day.

He said: “”They (Labour) are a morally bankrupt party who called this election early simply because they knew that Ukip could go on and win and had the momentum.”

Mr Nuttall said Ukip was “statistically the most working-class party in Britain” and added: “You don’t come within 600 votes of taking a Labour stronghold and not make it a target for next year’s general election.”

Mr Cameron, visiting a school in his Witney constituency, said the general election in May would be “the most important in a generation”.

“This speaks to a wider truth that if you vote Ukip, you are in danger of getting a Labour government with Ed Miliband as prime minister, Ed Balls as chancellor,” he said.

“You’ll get no action on immigration, no European referendum and, most importantly, you won’t get a continuation of the plan that’s delivering success for our economy and security for our people.

“That is the wider lesson of last night. We have seven months to demonstrate that only a Conservative government can give people the stability and security we all want to see.”

Former home secretary Jack Straw said Labour should have performed better in the Heywood and Middleton by-election and should have been stronger on getting its message on immigration out to voters.

But he said the result, along with Clacton, signalled a catastrophe for the Conservatives.

The Labour MP told Sky News: “We could and should have done better.

“That said, bearing in mind that our share of the vote went up, albeit by one percentage point, that there was a swing in our favour against the Conservatives by 8% points, so as Ed Miliband has just said, we’re not complacent about this.

“This should have been a better night for us but it was nothing compared to the catastrophe for the Conservatives.

“I come from Essex, I know Clacton. Clacton is where people vote Conservative with their breakfast, lunch, dinner and tea, and they didn’t.”

He added: “There are lessons in this by-election result (Heywood and Middleton).

“We were right to concentrate on the NHS. We have also, however, got to be stronger about our messages on immigration as well.”

In his acceptance speech Mr Carswell explained his decision to stand down after defecting from the Tories.

“I resigned from Parliament to face this election because I answer first, foremost and last to you, you are my boss, I will not let you down,” he said.

“To my new party I offer these thoughts: humility when we win, modesty when we are proved right. If we speak with passion, let it always be tempered by compassion. We must be a party for all Britain and all Britons: first and second generation as much as every other.

“Our strength must lie in our breadth. If we stay true to that there is nothing that we cannot achieve.

“Nothing we cannot achieve in Essex and East Anglia, in England and the whole country beyond.”

Ukip’s next target is Rochester and Strood, where Mr Carswell’s fellow defector Mark Reckless is hoping to return to Parliament.

Mr Carswell said: “In Rochester as in Clacton I believe voters will reject negative campaigns by old party machines.”

Mr Watling said he wanted to stand as the Tory candidate at next year’s general election.

He said: “I intend to stand here next May at the general election when this country will face a clear choice of who they want to be the leader - David Cameron or Ed Miliband.”

Labour’s Tim Young said: “I would also like to thank Mr Carswell, who of course none of this would have been possible. I wish him well. Having been born in Clacton and brought up here I truly care about Clacton and we will always continue to hold you to account Douglas, but I congratulate you on your victory.”

Howling Laud Hope, of the Official Monster Raving Looney Party, joked: “One little message for Mr Carswell, come seven months’ time in May will you cross the floor and join the loonies?”