Washington - US legislators worked behind closed doors through Saturday seeking agreement on a US finance rescue plan as a weakened US President George W Bush wrestled with a revolt from within his own Republican ranks on a tense Capitol Hill.

House of Representative Republicans continued to block approval of the mammoth 700-billion-dollar liferaft for the mortgage-debt-gone- bad crisis that has drained credit lines dry and is spreading financial troubles abroad.

Bush has pleaded on a near daily basis for speedy passage of the largest government bailout in US history, saying Saturday in his weekly radio address that he understood the moral outrage of the US public over being asked to "pay for mistakes on Wall Street."

"If it were possible to let every irresponsible firm on Wall Street fail without affecting you and your family, I would do it," he said. The expenditure represents one-quarter of the current US budget. Hundreds of thousands of homeowners have faced foreclosure or walked away from unaffordable mortgages in the crisis, depressing home values.

In recent days alone, the crisis has claimed one US bank, Washington Mutual. Britain's ailing Bradford & Bingley building society is about to be nationalized, and Belgian-Dutch banking giant Fortis was forced to deny rumours that it was experiencing liquidity problems as its shares dropped to their lowest level in 14 years.

Speaker of the House Nancy Pelosi said Saturday that she hoped differences over Bush's request for the lifeline "could be resolved" Saturday and final legislation could be brought "to the floor Sunday night or Monday morning."

But Representative Roy Blunt, the chief negotiator for House Republicans, said he was "not moving on any kind of artificial timeline."

Bush's economic gurus, Treasury Secretary Henry Paulson, a veteran Wall Street wheeler and dealer, and Federal Reserve chief Ben Bernanke, an academic economist and specialist in the history of the Great Depression of the 1930s, have tried to convince Congress for days that the financial system will collapse without immediate approval of the plan.

"Our entire economy is in danger," Bush told radio listeners. "The rescue effort we're negotiating is not aimed at Wall Street - it is aimed at your street."

Angry voters have been clogging e-mail inboxes and phonelines with protests against the unprecedented bailout of unregulated Wall Street risk takers who have caused the crisis.

Still stinging over their loss of majority in 2006 as Bush's popularity plunged, House Republicans now have a worried eye on November 4 presidential and congressional elections and want to put as much distance between them and Bush as possible.

Then too, Republicans in the House of Representatives also tend to be more fiercely opposed than their Senate colleagues to government regulation and interventions into capital markets. Many believe the market should be allowed to sort out the crisis by itself.

Democrats, who have held the majority in Congress for two years, are in the politically precarious position of being allied with Bush, who has the worst approval ratings for any president in more than 30 years. That's why the centre-left party is insisting that a majority of Republicans in Congress get behind the bill to provide the political cover of a bipartisan plan.

The 700-billion-dollar plan, pitched by Bush in a moment of urgency just last week as the investment banking industry collapsed, would allow the government to buy up "toxic" assets to sell off later, when the housing market stabilizes.

Democrats in both chambers along with Senate Republicans have already wrested concessions from the White House to allow limits on executive compensation in firms being helped, to insist on partial government equity stakes in the companies and on a bipartisan oversight panel for the bailout.

House Republicans want to solve the mortgage debt crisis by getting Wall Street firms to purchase insurance on mortgage-backed securities and cutting taxes and relaxing regulations on the industry, Bloomberg financial news agency reported.

Paulson and Bernanke have already rejected the insurance idea. The Washington Post compared such a plan to insisting a heart attack patient buy health insurance before being wheeled into the operating room.

The White House believes that if the government purchases the bad mortgage debts and related securities, finance firms will be freed up to resume the flow of credit to consumers and businesses that is now frozen. Foreign firms which have purchased the unregulated and high- risk mortgage debt securities could also benefit from the plan.

"The final cost of this plan will be far less than the 700 billion dollars," Bush said in the radio message. "Many of these assets still have significant underlying value because the vast majority of people will eventually pay off their mortgages."