WASHINGTON — The Senate is expected to reject decisively a House bill that would delay the full effect of President Obama’s health care law as a condition for keeping the government running past Monday, as Senator Harry Reid, the Democratic majority leader, expressed confidence that he had public opinion on his side.

Angering Republicans who lead the House, Mr. Reid kept the Senate shuttered on Sunday, in a calculated move to stall action on the House measure until Monday afternoon, just hours before the government’s spending authority runs out at midnight.

Without a complete capitulation by House Republicans, large sections of the government would close, hundreds of thousands of workers would be furloughed without pay, and millions more would be asked to work for no pay.

Polls show that the public is already deeply unhappy with its leaders in Congress, and the prospect of the first government shutdown in 17 years would be the latest dispiriting development. With a temporary shutdown appearing inevitable without a last-ditch compromise, the battle on Sunday became as much about blaming the other side as searching for a solution.