WASHINGTON — As the country’s major freight railroads braced for a possible strike among their employees, the North Country’s House representatives voted against a measure that would make the strike illegal.

For over two years, railroad employee unions had been negotiating a contract with the corporations that run the U.S. freight rail system. Employees were pushing for paid sick leave, which they do not currently receive, and more flexibility in their schedules, as well as more substantial raises and more hiring. The corporations have largely refused to accept such terms.

An agreement was thought to be reached in September, after direct involvement by President Joseph R. Biden and Labor Secretary Martin J. Walsh, but a number of unions have rejected that agreement because it lacked significant sick leave policy changes. The unions renewed their calls for a strike this month that could cripple the U.S. economy. That pushed President Biden to request Congress use the special powers it has over the nation’s rail network to enforce the agreement anyway.

The Senate passed a resolution Thursday that would put in place the rail labor agreement reached by the White House, railroads and labor unions in September, but rejected a separate measure to provide an additional seven days of sick leave to workers.

The rejection of the sick leave resolution serves a blow to rail union workers who held up the bargaining process and have threatened to strike Dec. 9 unless they get the additional sick leave. The passed resolution would prevent unions from striking by imposing a contract agreement.

The Senate voted 80-15 to pass the labor resolution, which would enact contract agreement provisions including one of the largest wage packages in nearly five decades, according to its advocates, as well as increased health benefits.

The resolution now heads to President Biden, who is expected to sign it.

Several Democrats, including New York Sen. Kirsten E. Gillibrand, voted against the labor deal because it didn’t include the sick leave provision, which failed 52-43. Both resolutions needed at least 60 votes to pass.

On Wednesday, the House voted 290-137 to approve the labor resolution and 221-207 to pass the separate sick leave bill.

Reps. Elise M. Stefanik, R-Schuylerville, and Claudia L. Tenney, R-New Hartford, who will be sworn in to represent western Jefferson County, the Finger Lakes and part of Western New York in January, voted against the measures.

In a statement, Rep. Stefanik blasted President Biden for involving himself in earlier negotiations that failed, then asking Congress to pick up the pieces.

“Joe Biden’s failed involvement in negotiations for a sham of a political win before the election led us to the brink a disastrous rail shutdown and further economic disaster,” she said. “At the last minute, he doubled down on his weakness and passed the buck to Congress to bail him out of another economic crisis. This is one more crisis resulting from one-party Democrat rule’s failed leadership.”

Rep. Tenney, who regularly explains her major votes on her congressional website, said she doesn’t support using Congress’s power to force union workers to accept the contract.

“After President Biden failed to negotiate a new contract between the railroad companies and railway workers, he asked Congress to undermine the rights of these workers and impose his negotiated deal,” she said. “Rank and file union members rejected this deal, and this resolution ignored their opposition to this deal. While it is important to avoid a rail strike, this should be accomplished by good-faith negotiations, not by Congress imposing a deal supported by union bosses and railroad companies, but opposed by rank-and-file railway union members.”

Much of the union workers’ opposition to the contract was driven by a lack of sick days in the agreement. Rail workers currently receive zero paid sick days per year. Progressives in the House and Senate pushed for a separate vote on a resolution that would change that. Rep. Tenney said she voted against this because it also overrides traditional contract negotiation methods.

“This is exactly the opposite approach that Congress should have taken,” she said, adding that the “railway workers and railroad companies should have continued negotiating a deal that both sides accept. By changing the deal, this disincentivizes dealmaking in future negotiation processes, and instead incentivizes both parties to simply have Congress impose the provisions that they support, the opposite of how the process should work.”

CQ-Roll Call contributed to this report.