Cameron: All prisoners should serve sentence in full

Promising that a Tory government would be "tough on crime", the Conservative leader said: "Prison will not be a deterrent until people serve the sentence they are given by the courts. It's ridiculous the way people are let out before their sentences are complete," he said in an interview with the News of the World.

"The first step would be to scrap Tony Blair's parole reforms, which now allow 30,000 criminals a year to be freed on licence before they have even completed half their sentence."

Mr Cameron said he would give the courts powers to send people back to prison and he would put more police on the streets.But he also said that not enough was being done to rehabilitate prisoners. More effort should be made to cut reoffending rates, he said.

Mr Cameron urged activists to "fast forward to the new Conservative Party", amid a certain amount of grumbling that his revival of Tory fortunes had hit "pause". His first speech to the faithful since his astonishing oration to win the leadership last autumn showed signs of defensiveness after a torrid week that has marked the end of his honeymoon with the party.

He urged grassroots Tories to make "faster, deeper and wider" changes in areas such as candidate selection, but received some unwelcome advice himself from one of his most senior advisers. John Gummer, a member of one of Mr Cameron's policy groups, told his leader to apologise to UKIP, whom he dubbed "fruitcakes, loonies and closet racists" in a radio interview last week. Speaking on Radio 4's Any Questions, Mr Gummer made public criticisms voiced privately by some senior Conservatives.

The "closet racist" jibe prompted a bizarre riposte from the right-wing party. As the Tory leader prepared to address delegates inside the Manchester International Conference Centre, Nigel Farage, the UKIP MEP, was posing in the turret of an armoured personnel carrier parked in the street outside.

But Mr Cameron didn't rise to the bait in his first conference speech as party leader. He concentrated on policies such as helping first-time buyers and reducing the cost burden of childcare, where he said the Tories had to again "become the party of aspiration".

The Tories' own aspirations of building a comfortable poll lead over Labour have failed to materialise despite months of mostly positive media coverage. Behind the scenes, shadow cabinet ministers are beginning to express fears for the "fragility" of the new leader's efforts to turn his party around without the momentum of a poll boost.

An ICM poll found that six out of 10 voters thought the Tories had "not really changed much"The poll also found that the new leader was trailing the Chancellor by a significant margin, 32 points to Gordon Brown's 37. There is also dismay at reports of a £270,000 salary paid to Steve Hilton, Mr Cameron's right-hand man and the brains behind the party's rebranding as political optimists. "There's been quite a bit of muttering about that salary. No one is worth that kind of money," a member of the shadow cabinet said.

There is frustration, too, at Mr Cameron's failure "to go for the political jugular". A senior Conservative said that he had been " tearing his hair out" over Mr Cameron's failure to inflict more damage over the "loans for lordships" affair.