Ken Clarke has said the Conservatives will win the "battle against red tape" by sweeping away regulation and letting business get on with creating new jobs.
The shadow business secretary told the Tory conference firms were swamped by paperwork introduced by Labour.
Business leaders welcomed the comments, but called for Mr Clarke to impose a moratorium on all new regulation.
The former chancellor also said today's economic crisis was worse than in 1979 when Margaret Thatcher was elected.
The increase in unemployment to nearly 2.5 million would have left Labour champions of full employment, like Nye Bevan, "spinning in their grave", he said.
"We are set to to take over the biggest mess a Tory party has ever inherited from a Labour government in my lifetime," he said.
"It is amazingly true that Labour always winds up leaving behind an economic disaster.
"It has happened every time since the war. But this is far, far worse. It's worse even than Margaret Thatcher was confronted with in 1979."
Since 1998, regulation has cost companies a staggering £76 billion, which is clearly far too much
David Frost British Chambers of Commerce
Referring to deficit-reduction plans, including a one-year public sector pay freeze, announced earlier by shadow chancellor George Osborne, Mr Clarke said these showed how "serious" the party was and how it was now equipped for office.
Mr Clarke outlined measures to reduce costs for business, saying firms should be left to focus on creating new products and services and to make the most of a future upturn in the economy.
All "excessive" regulation would be scrapped and any new red tape introduced by a future Tory government would be offset by cutting restrictions elsewhere, he pledged.
"If an individual who wants to develop his own business can't feel the Conservative Party is a friend, what exactly are we about as a centre-right party?" Mr Clarke said.
All quangos and regulators would be subject to a "sunset clause" where they would have to prove their usefulness or be scrapped, he added.
Mr Clarke denied this would lead to a decline in standards, saying areas such as health and safety would be protected.
The British Chambers of Commerce (BCC) welcomed the news, claiming red tape was "handcuffing British business".
Director general David Frost said: "This is a positive sign that the Conservatives are starting to focus on the real issues that restrict business and growth.
"Since 1998, regulation has cost companies a staggering £76bn, which is clearly far too much."
But the BCC, along with the Federation of Small Businesses (FSB), also called on the Tories to do even more.
The FSB's national chairman John Wright said: "The proposals could have gone further by proposing a moratorium on all new regulations.
"The FSB believes that all new business regulations should be postponed for the duration of the recession and the first 18 months after recovery."
Mr Clarke also told the conference that Labour had presided over a sharp decline in manufacturing jobs since 1997 and promised more focus on supporting high-value, hi-tech manufacturers.
"We have paid a heavy price for that. Britain has got to make things again," he said.
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