With a split developing among Republican Senators over efforts to block gun control legislation from even reaching the Senate floor for debate, Democrats set up an initial parliamentary vote on Thursday that seems likely to pave the way for the start of formal debate on new gun restrictions.

Before the Senate adjourned for the day on Tuesday, Senate Majority Leader Harry Reid filed cloture on the Motion to Proceed to the Democratic gun measure; that means backers of the plan will need 60 votes to force the start of official debate on the plan.

A number of Republicans signaled on Tuesday afternoon that they would not join efforts by a small group of GOP Senators to prevent debate from even starting; that doesn't mean they will support the gun bill, as most said they simply believed it was an issue that should be debated.

"The American people ought to see where everybody stands on this," said Sen. Tom Coburn (R-OK).

Meanwhile, two Senators were still trying to forge a final deal on background checks for almost all gun sales, as Sen. Joe Manchin (D-WV) and Sen. Pat Toomey (R-PA) were said to be close to a deal on Tuesday night.

Manchin and Toomey set a news conference for 11 am on Wednesday to update reporters on their progress; it wasn't immediately clear whether Manchin and Toomey were going to be able to work out something that would be acceptable to a large number of Republicans.

"It would be a real slap in the face to the American people not to do something on background checks, on school safety, on federal trafficking, which everybody thinks is a good idea," said Sen. Reid, who vowed to push ahead with gun legislation, no matter the opposition from Republicans.

"I'm going forward on this regardless of whether it's a compromise or not," Reid told reporters just outside the Senate chamber.

Reid is likely to have 60 votes on Thursday to force a start to formal debate on the Senate floor.

Whether he will have that many later on this month - stay tuned.