The Senate took a first step toward ending the government shutdown — the longest government shutdown in history — Sunday, after a group of moderate Democrats agreed to proceed without a guaranteed extension of health care subsidies.

In a test vote, the first in a series of required procedural maneuvers, the Senate voted 60-40 to move toward passing compromise legislation to fund the government and hold a later vote on extending Affordable Care Act tax credits that expire Jan. 1.

Final passage could be several days away.

The agreement does not guarantee the health care subsidies will be extended, as Democrats have demanded for almost six weeks. Senate Democratic leader Chuck Schumer of New York voted against moving ahead with the package, along with all but eight of his Democratic colleagues.

A group of three former governors — New Hampshire Sen. Jeanne Shaheen, New Hampshire Sen. Maggie Hassan and Independent Sen. Angus King of Maine — broke the six-week stalemate Sunday, when they agreed to vote to advance three bipartisan annual spending bills and extend the rest of government funding until late January in exchange for a mid-December vote on extending the health care tax credits.

The agreement also includes a reversal of the mass firings of federal workers by the Trump administration since the shutdown began on Oct. 1 and would ensure that federal workers receive back pay.

Senate Majority Leader John Thune quickly endorsed the deal and called an immediate vote to begin the process of approving it as the shutdown continued to disrupt flights nationwide, threaten food assistance for millions of Americans and leave federal workers without pay.

“The time to act is now,” Thune said.

Returning to the White House Sunday after attending the Washington Commanders’ 44-22 loss to the Detroit Lions at Northwest Stadium, President Donald Trump did not say whether he endorsed the deal. But he said, “It looks like we’re getting close to the shutdown ending.”

But a lot will need to happen in the coming days, including bringing the U.S. House back in session. House lawmakers haven’t been in session since Sept. 19, when they passed the original continuing resolution.

This was the first time the Senate worked through a weekend since the shutdown began at the start of October.

Senate Chaplain Barry Black has been offering opening prayers that address the pain the shutdown is causing. “Guide our lawmakers as they seek to set the captives free by reopening our government,” he said on Sunday.

Air travel problems grow as shutdown continues

Thousands of flights were canceled or delayed over the weekend and problems for air travelers are only expected to get worse this week.

The Senate’s rare Sunday session was held as lawmakers struggled to overcome an impasse that has left the government shuttered for 41 days.

Hundreds of thousands of federal workers have gone without paychecks during that time, including air traffic controllers, who are increasingly calling out sick.

“It’s only going to get worse,” Transportation Secretary Sean Duffy said of the delays and cancellations, in an interview on CNN’s “State of the Union.”

Duffy said looking ahead in the coming weeks ahead of Thanksgiving, “You’re going to see air travel be reduced to a trickle.”

The FAA mandated a 4% reduction in flight cancellations over the weekend and that is to go up to 6% on Tuesday, ultimately rising to 10% on Friday.

Across the U.S., more than 4,200 flights had been delayed and more than 1,500 had been canceled by early Sunday, with the numbers continuing to grow.

The Associated Press contributed to this report.