Updated

Rep. Bart Stupak conceded Monday that there's "nothing" to stop President Obama from reversing an executive order meant to keep restrictions in place separating taxpayer dollars from abortion coverage.

The promised executive order, which Obama is expected to sign along with the health care reform bill, was pivotal to Stupak agreeing to drop his opposition to the legislation Sunday just hours before the package passed by a narrow margin.

The reversal earned Stupak the scorn of anti-abortion groups who claimed the executive order was flimsy and that Stupak, a Michigan Democrat, should not have caved.

In an interview with Fox News, Stupak acknowledged their concerns.

"There is nothing that would stop this president from, a month from now, a year from now, 10 years from now, repealing this executive order," he said.

But Stupak also said that if the president ever went back on his word, the decision could be challenged.

"Because it (has the) full force and effect of law, if the president would revoke it, there's nothing that would stop pro-life groups or pro-choice groups from going to court and (challenging) this executive order saying it should stay in force," he said.