Ken Clarke said the downturn was far worse than in the 1990s
A Conservative government would have to be much tougher on public spending than "Margaret Thatcher ever was", Shadow Business Secretary Ken Clarke has said.
In an interview with the Times, he said the Tories would have to cut spending more severely than in the 1980s.
Mr Clarke also described his party as being "vague" on possible tax increases, such as raising VAT.
But the former chancellor said that was because it was not something the Conservatives liked doing.
He said: "If you are going to increase taxes you have to look at all your revenues.
"But we are definitely going to have cuts in spending. We are vague about tax increases because we don't like them."
Mr Clarke, who will be 70 in July, said a future Tory administration would face a more difficult situation than he ever did as a minister in the past.
"This is the longest, deepest recession anyone alive can now remember," he said.
"In percentage terms the level of spending cuts we are contemplating is probably [going to] exceed those of any modern government.
"We are going to have to be much tougher on public spending than Margaret Thatcher ever was."
Mr Clarke said the current economic downturn was far worse than the recession of the 1990s.
"I would say we're going to be bouncing along the bottom for quite some time," he said.
"There are myriad uncertainties; we haven't got rid of any of the underlying problems. It's very fragile."
In the interview, Mr Clarke also said it was foolish to deny that some small businesses might be reluctant to employ female workers because of the possibility they could take long maternity leave.
But he added that to start reversing rights to maternity leave would be ridiculous.