The prime minister has set the scene for Budget tax increases to pay for more investment in key public services.

With health expected to be top of the chancellor's priorities when he unveils his Budget on Wednesday, Tony Blair said Gordon Brown would "lay foundations for further investment".

Press reports predict significant tax rises of up to £7.5 billion, with extra spending largely expected to go towards the NHS.

Writing in the Observer newspaper on Sunday, the PM said the Budget would "crystallise" the choice between more spending or lower taxes.

"The Budget will crystallise for the country a fundamental choice in values, not just policies," he wrote.

"Do we take the benefits of economic stability and sacrifice public services in favour of short-term tax-cuts, as the Conservatives would, or do we invest in the future as we intend to?"

"I have confidence we can win that political battle," Blair added.

But he said the government would seek to maintain its reputation for fiscal responsibility and prudence.

"The Budget will continue our drive to strengthen our public services and make Britain the most competitive and entrepreneurial economy in Europe. We take no risks with the economy," Blair wrote.

"This Wednesday's Budget will be from beginning to end a new Labour Budget."

There was support for extra investment from the Conservatives, but shadow chancellor Michael Howard said it had to be coupled with further reform.

"Without change that money will not deliver the improvements that everyone wants to see in our public services, especially our health service and I am very much afraid that what we will see on Wednesday will be more talk, more taxes, no change and no difference," he told Sky News.

But the health secretary pledged the reform process would continue.

"If we are asking people to put money into the NHS, and I actually think that as a country that is the right thing to do, then what you have got to demonstrate is that if you put resources in, you get results out," Alan Milburn told GMTV.