Every 16-year-old would be expected to devote their summer to "patriotic" national service, under radical Tory proposals for fixing Britain's "broken society".
School leavers would be encouraged to join six-week projects such as military training, working with the elderly and even travelling overseas to help in Third World countries, according to David Cameron.
Mr Cameron unveiled the latest stage of his fightback from a torrid summer during a visit to Bolton yesterday.
The Tory leader said he felt "very passionate" about the idea, saying: "This will make people feel proud about themselves and about their country."
Having enjoyed limited success after promising a "bare knuckle fight" with Prime Minister Gordon Brown over the NHS, he may choose to don gloves as he outlines plans for a National Citizen Service alongside boxing star Amir Khan.
Mr Cameron also launched a furious assault on critics within his own party, insisting that "blasts from the past" were putting the Conservative resurgence in peril.
Former deputy leader and chairman Michael Ancram published a pamphlet on Tuesday accusing the leadership of "trashing" its Thatcherite heritage, and calling for a return to "core" values.
But Mr Cameron slapped him down, saying: "I want all Conservatives to think carefully before they open their mouths.
"When you make changes you'll get blasts from the past who signify absolutely nothing. They are wrong.
"Political leadership is about taking a long-term approach. I don't think when Tony Blair was trying to change the Labour Party he spent the whole time worrying about what Tony Benn was saying."
Young people would not be legally obliged to take part in the National Citizen Service, but Mr Cameron said he hoped it would be too attractive to pass up.
Participants would be eligible for a cash sum on completion, with half going to a charity of their choice and the rest to the organisation that ran the project.
Mr Cameron said: "It will mix people from different countries.
"North and south, black and white, rich and poor. They will be putting something back into the community."