US President Barack Obama has warned that the economic crisis facing the country will turn into a "catastrophe" if lawmakers block his £640bn rescue plan.Mr Obama wants to pass a bill that would see about a third of the cash spent on tax cuts, with the rest devoted to spending on projects such as rebuilding roads, bridges and schools, to help stimulate the economy and end the recession.
However, the package has proved unpopular among some Republicans, who would like to see more tax relief and less spending.
They complain some projects would do little to stimulate the economy or create jobs.
Democrats, however, say the spending Republicans describe as wasteful amounts to less than 1% of the package.
A group of about 18 moderate Senate Republicans and Democrats are seeking an agreement of their own to trim the package by roughly £70bn.
Mr Obama warned that the consequences of inaction would be severe.
"If we do not move swiftly to sign the American Recovery and Reinvestment Act into law, an economy that is already in crisis will be faced with catastrophe," he said during a meeting with House Democrats in Williamsburg, Virginia.
In a speech at the Energy Department, he seized on data that showed new jobless claims at a 26-year high as evidence that time was of the essence.
"These numbers that we're seeing are sending an unmistakable message, and so are the American people, that time for talk is over," he said.
US Senate Majority Leader Harry Reid remained upbeat the measure would pass.
He said if there were no Senate progress on Friday, he would file a motion to set up a showdown procedural vote for Sunday.
"Our number one goal is to pass this bill," he said.
"They (the Republicans) cannot hold the president of the United States hostage."
Republican Senator John McCain, who lost to Mr Obama in the November presidential election, criticised what he called a Democratic rush to pass the bill.
"They are establishing a very partisan approach to the greatest domestic challenge we face," he said.