Washington (CNN) - The divisive issue of abortion is once again causing eleventh hour problems for House Democrats as they plan to move forward on health care reform.
Anti-abortion Democrat Bart Stupak of Michigan is asking for a vote on his language restricting taxpayer funding for abortion, and a group of female abortion rights Democrats came out of an emergency meeting in House Speaker Nancy Pelosi's office Friday evening visibly angry about the prospect.
Rep. Diana Degette, D-Colorado, told reporters a vote on Stupak's measure was a "non starter" and said "somewhere between 40 and 55" abortion rights Democrats would bolt from the bill.
"We are holding firm this time," she insisted. "If Mr. Stupak and a few members along with the Republicans decide to use this to take health care down, that loss of health care will be in their hands."
It's not yet clear how seriously Democratic leaders are considering allowing a vote on Stupak's abortion language, or in what form.
But Stupak told CNN he is in discussions with Pelosi.
"We had a good discussion with the speaker on the floor," said Stupak. "But there was no agreement and there's no agreement until we see it in writing and we get a chance to massage it."
One possibility appears to be allowing a separate vote on Stupak's abortion measure, which would go to the Senate independent of the health care bill.
If it's an amendment to the Senate bill, which the House is expected to vote on Sunday, and it passes, that could throw the whole complicated but carefully choreographed process of passing health care into flux.
It would mean sending the bill back to the Senate, instead of to the White House for President Obama's signature.
–CNN's Dana Bash, Evan Glass and Deirdre Walsh contributed to this report.