WASHINGTON – The Democratic-led Senate easily cleared a hurdle to averting a government shutdown after a Republican lawmaker ended a 21-hour speech aimed at using the measure to derail President Barack Obama’s signature health care overhaul.

Senators voted unanimously Wednesday to allow a temporary spending bill to be officially lain before the Senate, one of several steps needed to move forward with the measure. Another key vote is expected by Saturday, with a Tuesday deadline looming to keep the government fully operating.

But a showdown looms over a provision in the bill to defund the 3-year-old health care law, which aims to extend insurance coverage to millions. The Senate is all but certain to strip the legislation of that language, which Republican-controlled House of Representatives included in an attempt to dismantle Obama’s most important domestic accomplishment.

The question is whether the House will approve the bill if the Senate sends it back as a straightforward funding measure without the health care provision — or reject it and risk a federal government shutdown.

To avoid a partial government shutdown, a single version must be approved by Congress and signed by Obama by Tuesday. Officials pointed out that there is still time for the Senate to restore the funds for the health care law — and for the House to seek a more modest overhaul concession, perhaps a one-year delay in the requirement for individuals to purchase coverage or the repeal of a tax on medical devices that many Democrats oppose.

The issue has roiled the GOP, exacerbating the divide between hard-right conservatives and more moderate leaders who fear Republicans will get blamed if the government shuts down.

Encouraged by conservative groups, Texas Sen. Ted Cruz, a potential 2016 presidential candidate, spoke all night and through Wednesday morning in favor of using the spending bill to kill the health care law. He stopped talking after 21 hours, 19 minutes, with occasional remarks by other senators.

Then he simply sat down and joined every other senator in the 100-0 procedural vote. He said Republicans should rally against the measure in a vote scheduled Friday or Saturday on whether to cut off a delaying tactic on the spending bill itself.

The Senate’s top Democrat, majority leader Harry Reid, shrugged off Cruz’s effort. “For lack of a better way of describing this, it has been a big waste of time,” he said.

Republican leaders opposed Cruz’s effort, arguing that defunding the health care law simply won’t happen with a Democratic president and Democrats controlling the Senate.