FOX News has learned that as many as 140 House members are absent from Capitol Hill, despite the fact the House has yet to adjourn for the Christmas holiday.

With a current roll of 434, that number of missing representatives leaves the House operating with less than 300 members.

House rules require a minimum of 218 members for a quorum. If too few are present, the House is unable to conduct business.

Those missing are not just members who lost in November's elections or are retiring. In fact, a sizable number of those representatives are still on Capitol Hill.

House leaders are waiting for Senate action on a 9-11 responders health bill, hoping to pass the same bill in the House. 

They could also vote on a bill that would recognize the deaths of 1.5 million Armenians in 1915 as a genocide at the hands of the Ottoman Empire (which is now mostly Turkey).

The House adjourned Wednesday morning subject to the call of the chair, meaning that they are out, and can come back into session at any time, whether it's in five minutes or at midnight.

"We're kind of thin," House Speaker Nancy Pelosi (D-CA) conceded shortly after the House adjourned.