Mr Cameron is promised to tackle the causes of "social failure"
David Cameron has promised a future Conservative government would be committed to "long-term tax reduction".
In a speech in Birmingham, he called for the proportion of national income used for public spending to be cut "to create the space for cutting tax".
This was "both morally right and economically efficient", the Conservative leader said.
He criticised Labour for "reckless" economic management, adding that taxpayers "can't take any more pain".
Since Mr Cameron became Tory leader in 2005, he and shadow chancellor George Osborne have refused to promise tax cuts, instead emphasising the need for "economic stability".
His speech is likely to be seen as his clearest commitment yet to easing the burden of taxation if elected.
Setting out his party's public spending strategy, Mr Cameron said "sharing the proceeds of growth" - restricting increases in public spending below the rate of growth of the economy - would eventually allow tax cuts and reduced government borrowing.
He also said: "We need to start living within our means. Because in the decades ahead there will be pressure to spend more on the essentials - whether that's care for the older generation, equipment for our armed forces, or more prisons and police to keep us safe.
"At the same time, we have reached the limits of acceptable taxation and borrowing. With the rising cost of living, taxpayers can't take any more pain and the economy can't take any more pain without losing jobs to lower tax competitors."
Tax cuts could be achieved by being "careful, not casual" with money and "attacking" the causes of a bigger state and rising public spending.
Mr Cameron promised this would not mean slashing public spending, saying: "We will give public services the proper funding they need so that everyone in the country can have access to the services they need."
Instead, the Tories would cut spending by a programme of school reform, welfare reform and action to strengthen families, which would reduce the burden of expenditure.
The government would have to publish online the details of any spending over £25,000 online, while a whistleblower service would allow people working in the public sector to report waste.
Mr Cameron said: "After a decade of reckless spending under Labour, Britain needs good housekeeping from the Conservatives."
But Liberal Democrat Treasury spokesman Vince Cable said: "David Cameron's vision for the UK economy is just an empty shell.
"The Conservatives' attempts to make a virtue of having no policies will not convince anyone."