Mr. Obama’s advisers emphasized that many of the new steps he called for could be taken quickly by the Democratic-controlled Congress in a lame-duck session this year, instead of waiting until after the new president is sworn into office in late January. Several steps could be taken by the Treasury and Federal Reserve using their powers under current law, the advisers said.

At the Capitol on Monday, Speaker Nancy Pelosi would not commit to calling Congress back immediately after the elections to consider a stimulus plan, given the potential that Mr. Bush would veto it. House Democratic leaders met with economists and afterward said they would develop a package for increased spending on public works, health care subsidies for states, extended unemployment pay and food stamp assistance.

Obama advisers put the cost of Mr. Obama’s full economic stimulus plan at $175 billion, including $60 billion for the steps announced Monday.

Of the earlier $115 billion, $50 billion would be used to help states and to speed construction of roads and other infrastructure projects that create jobs. About $65 billion of it would be the cost of a second round of rebates to taxpayers this year.

Mr. Obama had initially proposed to offset the rebates’ expense with a new windfall-profits tax on oil companies, but the campaign indicated Monday that he would scrap that plan assuming that oil prices do not rise above about $80 a barrel. The shift was just one sign of how the economic crisis has shoved concerns about budget deficits to the sidelines.

Despite criticism from the McCain camp that increasing taxes would further endanger the economy, Mr. Obama has “no plans to change” his longstanding proposal to repeal the Bush tax cuts next year for households with an annual income of more than $250,000, said Jason Furman, Mr. Obama’s economic adviser. Under Mr. Obama’s plan, most individuals and families would get a tax cut, and in terms of total dollars, he would cut taxes on lower- and middle-income people more than he would raise them on upper-income people.

McCain advisers on Monday reiterated their argument that the higher taxes, together with Mr. Obama’s plan for expanded health care, would hit small businesses with costs they could ill afford. Many small businesses pay taxes as individuals. But the Obama campaign and independent fact-checking groups argue that relatively few would be affected by the tax increase on upper-income levels.