The U.S. Senate is poised on Thursday for a vote to advance a bipartisan gun control bill that supporters hope will help curb the mass shootings that have rocked the country, in what could be the first new federal gun legislation in decades.

The 80-page Bipartisan Safer Communities Act would encourage states to keep guns out of the hands of those deemed to be dangerous and tighten background checks for would-be gun purchasers convicted of domestic violence or significant crimes as juveniles.

It does not include more sweeping gun control measure favored by Democrats including President Joe Biden such as a ban on assault-style rifles or high-capacity magazines. Biden renewed calls for action following a pair of high-profile shootings in Buffalo, New York, and Uvalde, Texas.

The legislation will need support from 60 of the Senate's 100 lawmakers in Thursday's procedural vote, which is expected around midday. If the vote succeeds, lawmakers could vote on passage as early as Thursday afternoon but no later than Friday.

With the chamber split 50-50, it will need the support of at least 10 Republicans to advance. Democrats were optimistic after 14 Republicans supported an initial step forward on Tuesday.

Senator Chris Murphy, the lead Democratic negotiator on the bill, predicted that "close to 20 Republicans" would vote to move toward passage on Thursday, and described the legislation as a potential watershed for further action.

"Once Republicans start voting for gun safety bills, they will find out that there is enormous political benefit and there's just not that much political downside," Murphy told CNN. "I think you will see the opportunity for compromise in the future."

But Republicans have tried to dissuade Democrats from making such predictions, saying the success of the current legislation would be unlikely to change their party's attitude toward guns.

Republicans who back the bill insist that it does not erode the rights of law-abiding gun owners, are among their most ardent constituents.

"It does not so much as touch the rights of the overwhelming majority of American gun owners, who are law-abiding citizens of sound mind," said Senate Republican leader Mitch McConnell, who backs the legislation.

But Republican supporters have faced criticism over the legislation, which is opposed by the National Rifle Association, the nation's biggest gun lobby.

The bill provides funding to help states adopt "red flag" laws to keep firearms out of the hands of those deemed a danger to themselves or others. It would also fund alternative intervention measures in state where red flag laws are opposed and provide for enhanced school security.

It closes the "boyfriend loophole" by denying gun purchases to those convicted of abusing intimate partners in dating relationships, and allows states to add juvenile criminal and mental health records to national background check databases.

Senator John Cornyn, the lead Republican negotiator on the bill, was booed last week as he discussed its contents during a speech before a Republican Party convention in his home state of Texas.

Senator Richard Durbin, the chamber's No. 2 Democrat, said the bill would provide $4.5 billion in funding to the Justice Department, the Department of Health and Human Services, and the Department of Education. A Republican aide estimated the measure's overall price tag at $13.3 billion, saying the cost was fully offset by funds from elsewhere in the federal budget.