A Christmas Eve vote on tax reform is likely if Republicans win enough support to pass the legislation, a key lawmaker said Wednesday.

"I do think if you had to pick a date by which we pass it through the House and the Senate, it would be Dec. 24, right?" said Rep. Patrick McHenry, R-N.C. "Simply driven by human nature and what has happened raditionally."

McHenry is the House GOP's chief deputy whip, meaning he helps lead the team responsible for rounding up votes and determining when they have enough to pass legislation.

Speaking at an event in Washington at the Financial Services Roundtable, a finance industry group, McHenry said he is "optimistic" about passing tax reform this year.

Republicans haven't introduced legislation, but they aim to pass a bill by the end of the year, an extremely ambitious timeline. Many lobbyists and other tax watchers see that goal as unrealistic.

In the past, key votes on major legislation have come right before or during the holidays.

Former President Barack Obama's healthcare law passed the Senate on Christmas Eve in 2009. The fiscal cliff legislation, resolving the fate of the Bush tax cuts, passed in the very early hours of New Year's Day in 2013.