Leaders of the US congress have reached a tentative deal with the administration of George Bush, the US president, on a $700bn bail-out for the country's troubled financial institutions.
"We've made great progress," Nancy Pelosi, speaker of the House of Representatives, said early on Sunday after a night of marathon talks.
Henry Paulson, the US treasury secretary, who under the rescue plan would have unprecedent powers to use taxpayers' money to buy up bad debt, said: "I think we're there."
"I think we are going to be able to have an announcement tomorrow, but these are difficult issues," he said.
"The refusal to agree to this package would have meant that everybody would run for cover and the markets would have spiralled downwards because there were so many expectations of this $700bn package," he said.
"It is very import to emphasise that we are in completely uncharted territory ... given the gravity of the situation the costs of doing nothing would have been enormous."
Several polls this week showed many Americans were sceptical of the package backed by Bush.
In one poll, 55 per cent of people said they did not believe the government should be responsible for bailing out private companies with taxpayers' money, even if the collapse could damage the economy.
Referring to his own senate office, he said, "We had, I'm going to guess, 3,500 calls this week about this particular issue. I've had 95 calls in support of it if that gives you any indication."
"We understand that there will be a supervisory board which will oversee this programme and there will be some limits on the golden parachutes ... the enormous payouts given to senior executives when they leave financial institutions," she said.
But seeking to persuade Americans to support the deal, he said: "The failure of the financial system would mean financial hardship for many of you.
"The result would be less economic growth and more American jobs lost. And that would put our economy on the path toward a deep and painful recession."
Both Democrats and Republicans have expressed disquiet that so much money from taxpayers would go to private companies, but Bush assured voters in his radio address that over time the value of those assets would rise again.
"This means that the government will be able to recoup much, if not all, of the original expenditure," he said.