Speaker Nancy Pelosi and top Democrats are making a last-ditch attempt to salvage a bill to renew expired surveillance tools Wednesday amid mounting opposition from Republicans and liberals in their own party, but it's still unclear whether the gamble will succeed.

Hours ahead of the scheduled floor vote, Pelosi and her top deputies were still whipping their members, with a growing number of progressives privately saying they would oppose the bill, according to people familiar with the discussions.

Pelosi told Democrats on a private caucus call Wednesday morning that they were still counting votes and hoped to have an update soon. But several senior Democratic aides were already predicting that leadership could yank the bill from the floor given the lack of support in both parties, or that the rule for considering the legislation would fail to win enough support to pass, tanking the underlying legislation.

"We'll act upon it today one way or another," Pelosi told reporters as she left the House floor, although she wouldn't predict whether the measure would pass or what version of the legislation would be considered.

"We'll see, we'll see," Pelosi added.

The House Rules Committee passed the Senate-version of the bill by party line vote, setting the stage for some drama on the floor.

Troubles with the bill emerged late Tuesday, with the threat of a veto from President Donald Trump that prompted House Minority Leader Kevin McCarthy (R-Calif.) to personally ask House Majority Leader Steny Hoyer (D-Md.) to pull the bill.