Gordon Brown has today said he would carry on Tony Blair's policy of reform if he became the next prime minister.
Speaking the day after his pre-Budget report, the chancellor said that "whoever was running this modern Labour party" would have to continue reforming and investing in public services.
He accused the Conservatives of failing to recognise this, and of planning to cut investment in public services, saying their new proposals were just "rebranding" old ideas.
Britain would only be able to compete in a globalised world with "modernised public services and a strong, efficient, dynamic economy, and that is what we are about", Mr Brown told Today.
And this would only be achieved by continued investment - something the chancellor said the Conservatives were unwilling to do.
David Cameron is expected to be crowned new Tory leader this afternoon, and has promised to share the proceeds of economic growth between public spending and tax cuts.
But during his statement to the Commons yesterday, Mr Brown tore into this policy, saying it would mean cutting investment this year and next year, and he continued this attack today.
"What we have got here in the public spending and economic policies of the Conservatives is simply a rebranding of the policy with a new gloss on it, new terminology but it is actually the same policy, which is cuts in public spending," the chancellor said.
Looking ahead to when he might be leading the party, Mr Brown added: "The issue will be which party and which government is going to equip this country best for the future challenges and will provide prosperity not just for some people but for all people in our country.
"That will require modernised public services and a strong, efficient, dynamic economy and that is what we are about."
Questioned whether he was too young to fight an election against Mr Cameron, who at 39 is 15 years younger than the chancellor, Mr Brown cited the fact that he had two-year-old child, saying: "I feel pretty young."
And he pointed out that William Hague was an even younger Tory leader, who "didn't exactly change the policy of the Conservative party".
The new Conservative leader is due to be unveiled at 3pm this afternoon.