David Cameron has spoken out after his party was hit by a defection to Ukip and a ministerial resignation on the eve of the Conservative party conference.
Speaking to Andrew Marr, the Prime Minister said Reckless's decision was "senseless and counterproductive".
The defection of a second MP to Nigel Farage's eurosceptic party will be a bitter blow to a Conservative party attempting to present a united front ahead of next year's general election
Cameron argued that to achieve change on the issues that most concerned Ukip voters the only way was to vote Conservative.
"If you want to have a European referendum, if you want to have immigration controlled, if you want to get the deficit down, if you want to build a stronger Britain that we can be proud of, there is only one option and that is to have a Conservative government after the next election", Cameron said.
On Saturday, Reckless told the Ukip conference in Doncaster that voters felt “ripped off and lied to,” and that the Conservative leadership was "part of the problem that is holding our country back".
A by-election will now be held in Reckless's seat of Rochester and Strood. Cameron also spoke on Conservative plans for welfare reform, EU renegotiation and his conversation with the Queen where he was caught on camera saying the sovereign "purred" with delight at the result of the Scottish referendum.
Responding to whether he would recommend a vote to leave the EU if renegotiation was unsuccessful, Cameron said:
If I don’t achieve that it will be for the British public to decide whether to stay in or get out ... I have said this all my political life: if I thought that it wasn’t in Britain’s interest to be in the European Union, I wouldn’t argue for us to be in it.
In the Mail on Sunday, George Osborne outlined Conservative plans for welfare reform in the event of a Tory victory next year. A Conservative government would cut the welfare cap from £26,000 to £23,000 a year and scrap job seeker's allowance for young people out of work for more than six months.
The Tory leader commented:
At heart, I want us to effectively abolish youth unemployment. I want us to end the idea that aged 18 you can leave school, go and leave home, claim unemployment benefit and claim housing benefit. We shouldn’t be offering that choice to young people; we should be saying, ‘you should be earning or learning’.