The government is to blame for the crisis at Northern Rock, Conservative leader David Cameron has said.
Cameron wants greater transparency between lenders
Writing in the Sunday Telegraph, he accused Gordon Brown of presiding over a huge rise in public and private debt.
The Tories are also calling for the government to say what it knew about the bank's problems before it sought help from the Bank of England.
Chancellor Alistair Darling said the Tories were "fundamentally wrong in their analysis of what has happened".
Meanwhile, worried Northern Rock customers are still withdrawing money from the bank.
Mr Cameron said the lines of savers queuing to withdraw their savings from the bank "serve to remind us just how fragile the stability of the economy can be".
"The credit crunch, previously restricted to the City, has burst onto the high streets," he said.
"Under Labour our economic growth has been built on a mountain of debt.
"For all its past talk of prudence, the government has been on a spending and borrowing spree of gigantic proportions."
The government had to learn that "an economy built on debt puts economic stability at risk", Mr Cameron added.
He also called for changes to fiscal rules, including greater transparency between lenders about borrowers' credit histories.
Customers have been withdrawing money
"It is not enough for the chancellor simply to talk about common sense in banking," he said.
The shadow chancellor, George Osborne, also said that to end speculation and rumour the government had to say what it knew about Northern Rock's problems before it sought help from the Bank of England.
"What we're trying to do here is stop people following the latest story in the newspapers or the latest rumour and actually trust the advice that they're being given," he said on BBC TV.
"There is a genuine question about the handling of the economy over the last 10 years... and whether we have created an economy built on debt, on government debt and on consumer debt. And whether that has left us more exposed to economic instability and to the global financial turbulence."
Flood of regulation
Ken Clarke, the last Conservative chancellor, said the problems at the bank should not lead to tough new restrictions on borrowing.
"I think the development of ready access to credit is one of the best ways of boosting a market," he told , told BBC Radio 4's Broadcasting House.
"So I do hope the reaction to the recent nonsense is not that we need a great flood of new regulation, that everybody gets hair-shirted again."
Chancellor Alistair Darling and City watchdog the Financial Services Authority have repeatedly moved to reassure customers that the bank was still solvent.
Mr Darling, speaking on BBC Radio 4 The World This Weekend, dismissed the Conservative analysis of the credit crisis.
"David Cameron is wrong yet again on both things he says.
"Firstly in relation to the British economy - it is fundamentally strong and if you look at the previous shocks to the system we have had in relation to the collapse of the Asian stock market and the American stock market, Britain did not falter. Other countries did. We continued to grow.
"If you look at the government's borrowing and the government's debt, the position is infinitely better than it was when David Cameron himself was an advisor at the Treasury."