election candidates in TV debate 10 November 2014 Last updated at 06:24 By Sue Nicholson BBC News, Rochester The defection of the Conservative Party's second MP to the UK Independence Party will see an electorate of more than 73,000 in the Kent constituency of Rochester and Strood go to the polls in a by-election on Thursday 20 November. Mark Reckless, who won the seat for the Conservatives with a 9,953 majority at the last general election, triggered the poll with his announcement on the eve of the Conservative Party conference. He is among 13 candidates battling it out for the key seat, which could see a second parliamentary gain for Nigel Farage's party following the success of Douglas Carswell in Clacton last month. The five main candidates took part in a 40-minute debate, organised by BBC South East and held at the Corn Exchange, in Rochester, in front of an audience of 150 voters. Mr Reckless was first asked if his defection to UKIP was "a genuine change of heart or just a political stunt." He said one of the reasons for his decision was because he believed the Conservatives were not serious about renegotiating the UK's relationship with the European Union. He had believed the Conservatives were the only party which could deliver an in/out referendum on Europe but had now "come to the conclusion that David Cameron is simply not serious about this." "David Cameron could probably get some changes round the edges on benefits but the main issue is the unlimited number of people who can come from these countries and come and work in the United Kingdom," Mr Reckless told the audience. Conservative candidate Kelly Tolhurst challenged him: "You said a month ago that voting for UKIP would cause problems with regards to getting an EU referendum, David Cameron delivering a referendum. "If this is what you truly believe - if you really believe we can take action in Europe, why is it you've defected to UKIP and why haven't you stuck behind this Conservative-led government to allow David Cameron to have that renegotiation to try to achieve the things you say you want?" she asked. Mr Reckless said: "Because I don't believe David Cameron and the Conservatives are credible on Europe." Ms Tolhurst said she wanted "action, not just talk on uncontrolled immigration," and had already pushed the prime minister on the subject during his campaign visits to the constituency. Labour's Naushabah Khan said she wanted a "clear and deliverable policy" on immigration, with border controls such as fingerprinting. Geoff Juby, for the Liberal Democrats, said stopping immigration was "a two-way street." There's nearly two million [UK citizens] living in Spain so if you stop the Spanish coming here, will they chuck those people out? How will we deal with them? I'm in favour of Europe," he told the panel. The Green Party's candidate, Clive Gregory, referred to the economy, making the point the lack of jobs in the UK was being caused by "the banks crashing the system" rather than immigration. During the debate, Mr Reckless defended his decision to quit the Tories as "the honourable thing to do." He said he had also defected because he did not feel the Conservatives were keeping the promises they made in 2010 to cut the deficit and had failed to cut immigration, as promised. "They've kicked that can down the road," he said. Having taken that decision that I couldn't keep the promises I made in 2010 as a Conservative but I could with UKIP, I switched to UKIP and I felt it was right to hold a by-election because I was elected with people who had voted for me as a Conservative candidate. He said he and Mr Carswell were the only two MPs in 30 years to resign their seats and put the decision to voters. But Mr Gregory declared his decision "a cynical stunt" designed to get "maximum publicity for the UKIP machine" just six months before a general election. He described it as an "absolute disgrace." "The Greens are now the only true opposition in politics - everyone else is only a faction of the Conservative Party," Mr Gregory told the audience. Another hot topic for the panel was the crisis surrounding the Medway Maritime Hospital, which was put into special measures by the government more than a year ago following concerns about high mortality rates and poor standards of care. Further inspections by the Care Quality Commission this summer found it was still failing to meet required patient care standards. All five candidates agreed the issue was one of particular concern. Ms Khan claimed the hospital had been in a "state of decline" since Labour had lost power, and she promised her party would create an NHS Time to Care Fund to deliver more frontline staff. She said the money would come from "additional taxes on tobacco companies, and stopping tax avoidance at the top." But Mr Juby said there had been a "fundamental flaw" in the NHS under Labour and not enough doctors and nurses had been trained. He said the Medway towns faced the ongoing problem of there being too few GPs available to take over the practices of retiring colleagues. I think it goes back to Labour's GP contract. "GPs do not want to come and work in Medway," Mr Juby said. For the Conservatives, Ms Tolhurst said she was passionate about the Medway Maritime Hospital - which had saved her life last year - and it was unacceptable that it had been in special measures for more than 12 months. "I want to work with our neighbouring MPs, the administrators, the regulators, and the doctors to make sure we have a strong plan to bring that hospital out of special measures as soon as possible," she said. The Battle for Rochester and Strood: A BBC South East Special will be broadcast on Monday 10 November at 22:35 GMT on BBC1 and BBC Radio Kent, and at 23:30 GMT on the BBC News Channel.