Some GOP conservative leaders are scrambling to find an antidote to Donald Trump.

A group met in Washington Thursday to figure out if they still have a shot at preventing Trump from clinching the GOP nomination. Broadcast sources say there was "absolute consensus" in the closed-door meeting on trying to stop Trump from getting the number of delegates needed to clinch the nomination, but that there was a "real division" about launching a third-party challenge if Trump ultimately becomes the nominee.

One possible alternative to Trump says he's not interested, as Speaker of the House Paul Ryan (R-Wisc.) brushed off the idea that he could be drawn into the presidential race. "It's not going to be me. It should be somebody running for president," says Ryan.

But the house speaker is not stepping away from the prospect his party might be heading toward a contested convention. "This is more likely to become an open convention than we thought before, so we're getting our minds around the idea that this could very well become a reality."

Trump's team is encouraging Republicans opposed to Trump to rethink their strategy. "We are going to be our nominee and, you know, some of these guys are gonna have to decide how much damage they are willing to do to the party because they don't like that," says Senior Adviser to the Trump Campaign Barry Bennett.

The potential for a contested convention is certainly on the minds of both Sen. Ted Cruz and Gov. John Kasich. "If we're neck-in-neck and neither of us are at 1,237, then it's a battle for the remaining delegates, then it's actually how a convention normally operates," says Cruz. "It is unlikely that anybody is going to achieve enough delegates to avoid a convention," says Kasich.

Trump would need to win a little more than 50 percent of the remaining delegates to reach the mark of 1,237 delegates for the nomination.

GOP leaders have also reportedly discussed forming a joint Cruz-Kasich ticket. but the source says no one is committed to that idea yet.