WASHINGTON (CNN) -- Senators have reached a tentative bipartisan deal to avert the so-called "nuclear option" -- a controversial rules change in the Senate -- sources in both parties told CNN.
At issue is what Democrats call unnecessary, lengthy delays of seven of President Barack Obama's nominees being filibustered by Republicans.
The deal would lift the filibusters and allow confirmation votes, but in exchange Democrats would agree to withdraw two nominees to the National Labor Relations Board.
Obama put them in office during a period when he says the Senate was in recess. The president would nominate two different candidates for the board, which for years has been a target of conservative Republicans unhappy with its composition and decision making they consider pro-union or anti-business.
Sen. John Hoeven, R-North Dakota, told CNN that was the key to the deal, and fellow Republican Sen. John Cornyn said the move would help overcome the GOP's opposition to the president's other nominees.
"I'm glad the administration has agreed to withdraw the two unconstitutional appointments of these two NLRB members and substitute two others," Cornyn said. "It relieves a lot of the objections we had to this overreach by the executive branch. And it sounds to me like, at least for today, that it's averted the nuclear option."
Republicans disputed the appointments of Sharon Block and Richard Griffin, and the Supreme Court agreed to take up the case.
The NLRB, which weighs labor disputes, is supposed to be non-partisan but it has become one of the most politically polarized agencies in Washington.
CNN reported Monday about secret weekend talks that formed the basis for the deal between Sen. John McCain, R-Arizona, and Senate Majority Leader Harry Reid, D-Nevada. An aide to Sen. Chuck Schumer, D-New York, says he, too, was heavily involved in the negotiations.
On the Senate floor on Tuesday, Reid said a deal was near.
"We still have a few more 'I's' to dot and 'T's' to cross," Reid said. "It is a compromise. I think we get what we want, they get what they want."
He also praised McCain for his pivotal work in crafting a deal, "even at his own peril."
Tuesday's development comes after senators failed to reach a deal on avoiding the confrontation -- a partisan threat by Reid that would change the rules on filibusters.
After a nearly four-hour meeting stretching late into Monday night, senators said no deal was reached, though many left Capitol Hill with a sense that a solution would be found soon.
The Senate voted on Tuesday to proceed with the nomination of Richard Cordray to head the Consumer Financial Protection Bureau. Republicans have stalled the confirmation process for months.
While Democrats control the Senate, they don't have the 60 votes necessary to break a GOP-led filibuster.
Reid would have used "nuclear option" to change the rules in order to prevent filibusters of executive branch nominations, allowing them to be confirmed on a simple majority vote of 51.
Reid has warned Republicans if they continued blocking some of Obama's Cabinet and agency picks, he would make the drastic move without their consent. Such a move would bring sharp opposition from Republicans, who have threatened to block other legislation as a consequence.
At issue is a disagreement over three of the nominees -- two for the NLRB and one to head the Consumer Financial Protection Bureau. They were tainted in the minds of Republicans because they originally had been nominated as "recess appointments" by Obama -- even though senators said they were in session.
Republicans have remained steadfast against confirming them until the Supreme Court decides if the recess appointments were constitutional, something the high court is considering.
Any use of the "nuclear option" could stall passage of several important items moving through Congress, like tax reform, judicial nominations, government spending bills and a debt ceiling increase.
Even a relatively modest rewrite of student loan laws could be in jeopardy, meaning students headed to school this fall would have to pay higher interest rates.
CNN's Ashley Killough, Lisa Desjardins and Kevin Liptak contributed to this report.