'It's not where you come from that counts – it's where you are going'

David Cameron pledged yesterday to turn Britain into an "aspiration nation" as he insisted he would fight the 2015 election as a "modern compassionate Conservative".

In his 50-minute closing speech to the Tory conference, the Prime Minister rejected Labour's portrayal of "cartoon Conservatives who don't care" and who defend the interests of the rich. Spelling out his values and what makes him tick, he made clear that championing "aspiration" was not a throwback to Thatcherism, which Tory strategists admit is now seen as a "selfish and survival of the fittest" creed.

Instead, Mr Cameron promised to be on the side of the "strivers" who work hard to get on, pledging that the welfare and education systems would help them fulfil their ambition and potential.

Critics will contrast his attempt to reclaim the One Nation mantle from Labour with right-wing signals from other ministers to the Tory faithful this week on crime, immigration and benefits. Mr Cameron positioned himself above that in a speech, aimed more at the country than his party, in which he trumpeted plans for higher spending on the NHS and overseas aid.

His address was almost entirely rewritten in the past couple of weeks. Aides insisted that was not because of Ed Miliband's One Nation speech last week. But Mr Cameron did hit back at the Labour leader, saying: "We don't preach about one nation but practise class war; we just get behind people who want to get on in life. The doers. The risk takers. The young people who dream of their first pay cheque, their first car, their first home – and are ready and willing to work hard [for them]."

He went on: "While the intellectuals of other parties sneer at people who want to get on in life, we here salute you. They call us the party of the better-off. No: we are the party of the want-to-be-better-off, those who strive to make a better life for themselves and their families – and we should never, ever be ashamed of saying so… Line one, rule one of being a Conservative is that it's not where you've come from that counts, it's where you are going."

Defending a tougher welfare regime to prevent people choosing to live on benefits, Mr Cameron said: "Those who can should, those who can't we will always help… Work isn't slavery, it's poverty that's slavery. It's us, the modern compassionate Conservative Party, who lead the fight against poverty in Britain today."

The Prime Minister's other big theme was the global economy: "Unless we take difficult, painful decisions...Britain may not be in the future what it has been in the past," he warned.