Washington, DC (LifeNews.com) -- The leading pro-life Democrat in the House of Representatives says a total of 40 Democratic lawmakers would vote to oppose a health care bill on the House floor unless it explicitly included language banning taxpayer-funded abortion and insurance mandates on abortion.

Rep. Bart Stupak, a Michigan congressman, has been one of the leaders in making the government-run health bill the House is considering abortion free.

This afternoon, Stupak said he is "optimistic" that the House Energy and Commerce Committee will adopt pro-life amendments to the health care bill that would make it abortion free. The panel could vote as soon as Thursday on the amendments.

Should the committee reject the amendments, Stupak tells CBS News that he thinks three dozen Democrats will walk and repeatedly vote against the bill or rules for debate on it.

"I think if they do not have [the pro-life amendments] in there and President Obama says we are going to have a bill with nothing in there on abortion, I think it is going to backfire," he said. "I think we bring down the rule and it will be explicitly discussed in the health care plan one way or another."

Stupak said he is confident he will have "a minimum of thirty nine" Democrats who will join him in opposing the bill.

"If there is not direct language and we are denied our amendment we will focus our attention on the rule," Stupak warned.

Stupak said the pro-life and moderate Democrats would "demand" an up or down on the abortion funding limits before allowing the health care bill to move forward.

Before a bill can be debated on the House floor, the House Rules Committee adopts the rules for debate and Stupak's warning could mean votes against the rule both in committee and on the floor before the debate on the bill could get underway. That would block the legislation and could defeat the entire bill.

Stupak also responded to CBS about the comments President Obama made Tuesday night in an interview with Katie Couric about abortion and health care.

Obama said he did not want to "wade into" the issue of whether the health care bill would allow abortion funding and insurance mandates, and appeared to say he didn't favor allowing that.

Stupak said the abortion funding debate has to happen on the House floor eventually.

"You can't talk about health care and reproductive rights [without abortion]," Stupak said. "You cannot not talk about it. It is central to all of the things we have been doing."

"The president was elected to make tough decisions, just as I was elected to make tough decisions," Stupak said. "These are tough decisions, you don't run from them."

Stupak's number of 40 Democrats likely includes the 20, including him, who signed a letter to House Speaker Nancy Pelosi in June saying they will not support any health care restructuring bill that does not explicitly prevent abortion funding and coverage.

Pelosi received another letter yesterday from four more Democrats who didn't make the same absolutist statement but urged that abortion limits be included.

Sign Up for Free Pro-Life News From LifeNews.com