Tory MP Mark Reckless defects to Ukip

Appearing on stage to a rapturous reception at the eurosceptic party's conference in Doncaster, he said voters felt "ripped off and lied to".

"Today I am leaving the Conservative party and joining Ukip," he said.

On immigration, Mr Reckless said constituents needed to believe that Britain had control over who comes into the country and in what numbers, adding: "At the moment we do not have any sense of that."

He said: "The insanity of our immigration rules means that a second generation Briton wanting to bring granny over for a wedding, still less if they want to get married to someone from abroad themselves, will face huge difficulties, yet they will see an open door to immigration to anyone from the European Union."

He added: "Now does anyone left or right genuinely support an immigration system where we turn away the best and brightest from our Commonwealth, people with links and family here in order to make room for unskilled immigration from southern and eastern Europe."

He went on: "I promise to cut immigration while treating people fairly and humanely, I cannot keep that promise as a Conservative, I can keep it as Ukip."

Mr Reckless announced that he will quit as an MP so he can trigger a by-election and fight the Kent seat as a Ukip candidate.

He told activists he answered to his constituents and wanted to seek their permission to change allegiance.

"They are the boss and if I am to seek to represent them under different colours, I hope in a party that is closer to their values, then I shall ask their permission," he said.

"So I will resign my seat in Parliament, trigger a by-election and, your national executive allowing, stand for Ukip."

The surprise announcement, which comes on the eve of the Conservative party conference in Birmingham, is a further blow to David Cameron.

As he was introduced on stage by a clearly delighted Nigel Farage, the crowd broke out into whoops and cheers and continued to chant "Ukip, Ukip" throughout his speech.

Mr Reckless said he had endured a number of sleepless nights over the decision, telling the conference he had been a Conservative "as long as I can remember".

He added: "I do feel that the leadership of the Conservative party is part of the problem that is holding our country back."

Mr Reckless said he had made promises to constituents at the last election that the Government was failing to keep.

He said: "I also promised that we would make government live within its means like the rest of us had to. Yet, we will see in this parliament in just five years a Conservative-led government adding more to our national debt than even Labour managed in 13 years.

"And two weeks ago the three Westminster leaders promised to give £1,600 extra to every Scot.

"As well as fairness to everyone else in our country, I promised to help restore order to our public finances yet I find I cannot do that as a Conservative but I can do it as Ukip."

Mr Reckless said the Tories had made election pledges to do away with housing targets to stop green spaces being concreted over but the Conservative council in Medway, "under Government pressure", had increased its numbers.

He said MPs were now often little more than "agents of a political class".

Mr Reckless faces a tough battle to return to Westminster under the Ukip banner and appealed for activists to support his campaign.

At the 2010 general election he held the Rochester and Strood seat for the Conservatives with half of the vote and Ukip did not even field a candidate.

He said: "It is a decision I make from optimism, a decision that is borne of a belief that Britain can be better. And of my knowledge of how the Westminster parties hold us back but also of my belief in the fresh start Ukip offers."

"If we can win in Rochester and Strood as well as in Clacton and perhaps here in South Yorkshire, then we can show that Ukip can break through across the country and we will show once and for all that a vote for Ukip is a vote for Ukip," he added.

Voters feel disconnected from Westminster, but he added that this was "too mild a word".

"People feel ignored, taken for granted, over taxed, over regulated, ripped off and lied to," he said.

"Instead of championing their constituents' interests in Westminster, too often they champion their party's interests in their constituencies."

He added: "A Ukip which can do for our politics, what modernity has done for our society, a Ukip which is about hope and optimism, a Ukip which can safeguard our children's future and a Ukip which believes we are more than a star on somebody else's flag."

Mr Reckless dismissed the Prime Minister's promise of an in/out referendum on membership of the European Union.

He said: "I'm afraid I have reluctantly reached the view that he is doing so purely as a device. He has already pre-ordained his intended outcome, namely continued membership of the EU on something very close to the present terms.

"Everything else is for show.

"What the Prime Minister has in mind, and it's not even a secret at Westminster, is modelled on what Harold Wilson did in 1975 - a bogus renegotiation followed by a loaded referendum."

He added: "In this hall we want a straight referendum, an honest referendum. In or out, no fudge, no conjuring trick."

The Tories described Mr Reckless' defection as "completely illogical".

A Conservative spokesman said: "Mark Reckless' decision to join Ukip is completely illogical. He says he wants action on a European referendum, tax and immigration. The only party capable of delivering on these issues is the Conservative Party - and a vote for Ukip is a vote for Ed Miliband."

Ukip's prospective parliamentary candidate in the constituency, Mark Hanson, had been unaware of the plans to install Mr Reckless in the seat but told conference that he was happy to quit.

"I'm going to stand aside for Mark Reckless," he said. "The only question is what took you so long?"

Mr Farage praised Mr Hanson for the "selfless gesture".

Mr Reckless' decision to defect comes one month after former Tory colleague Douglas Carswell announced he was jumping ship.

Mr Carswell is fighting to win back his Clacton seat on a Ukip ticket in a by-election that will be held on October 9.

Mr Farage told the conference that polling shows Mr Carswell is on course to win with 56% of the vote, pushing the Conservatives into second on 24%.

The poll by Conservative peer Lord Ashcroft suggests that Ukip will also take seats in South Thanet - where the Ukip leader is standing - Boston and Skegness, Eastleigh and Thurrock.

Mr Farage said: "We fought the European elections, if you think about it, as a shot gun. We needed to put the message as far and wide as we possibly could, we needed to get every vote we could from Land's End to John O' Groats."

He added: "So now whilst we have to fight everywhere, we have to focus and target our resources both human and financial on the right constituencies, it's called targeting. We haven't declared yet how many target seats there are going to be, the reason for that is we don't know, because British politics is in the biggest state of flux it's been in my lifetime and things are changing very, very quickly."

Mr Farage told BBC News that Mr Reckless faces a harder fight in his constituency than Mr Carswell in Clacton.

"I am going to do everything I can to support Mark Reckless in that by-election. I shall be down there, I shall knock on doors, I shall do whatever it takes. This man has shown huge courage. He has thrown his lot in with us and we will do everything we can to get him elected."

Asked about other possible defections, he replied: "We have these conversations. Of course there are Conservatives I am talking to but there are Labour people too. There are Labour people who are deeply frustrated with Ed Miliband's leadership."