WASHINGTON - The political hot potato of abortion continues to vex politicians in both the U.S. and Canada, decades after most North American women won the legal right to terminate an unwanted pregnancy.

Abortion almost scuttled U.S. President Barack Obama's health-care reform bill, then ended up saving it. In 11th hour negotiations with pro-life Democrats, the president agreed to issue an executive order to make clear that the existing ban on federal funding of abortion would remain in place.

Those assurances secured enough votes to pass the legislation, which Obama signed into law Tuesday amid much fanfare.

But both pro-life and pro-choice activists were left seething. Pro-lifers have raged all week that the bill is the biggest piece of pro-choice legislation in decades, while abortion rights activists have assailed Obama for negotiating health-care reform at the expense of women.

In a country where most Americans consider themselves religious and almost all believe in God, it's an issue that doesn't appear to be going away anytime soon.

"There are religious communities throughout the U.S. that regard abortion as morally wrong - they're numerous, and because they're numerous, they're powerful," said John Green, a political science professor at the Bliss Institute at the University of Akron in Ohio.

"The fact that abortion became such an important part of the health-care debate is evidence of how deep-seated those beliefs are in this country."

In Canada, meantime, Conservatives are steaming about the very idea of the debate being revisited. A Liberal motion on overseas family-planning initiatives has been described by outraged Tories as a "transparent attempt to reopen the abortion debate."

The Liberals have put forward the motion in the House of Commons that urges the government to include "the full range of family planning, sexual and reproductive health options, including contraception" in its maternal health initiative at this summer's G8 summit.

The motion also calls on Ottawa to reject a ban on government funding for overseas family planning organizations that carry out or facilitate abortions, a hallmark of the previous George W. Bush administration.

On his third full day as president in January 2009, Obama overturned the eight-year ban.

Bev Oda, the Conservative minister responsible for foreign aid, told the Commons her government has no intention of reopening the abortion debate. She also denounced what she called the "rash, extreme anti-American rhetoric" of the motion, which she said would damage Canadian foreign policy efforts.

South of the border, election years often spark renewed debate on abortion. Adding to the mix are recent polls suggesting an increasing number of Americans say they consider themselves pro-life.

Another recent U.S. survey, by Quinnipiac University, suggested that 72 per cent of Americans were opposed to any public money in the health-care reform legislation being used to pay for abortions.

Polls in Canada routinely suggest, on the other hand, that a strong majority of Canadians are pro-choice. Statistics Canada has also found a decreasing number of Canadians consider themselves religious.

Thirty-seven years after the historic Roe versus Wade decision in the U.S. Supreme Court disallowed many state and federal restrictions on abortion in the United States, the issue is still at the centre of fierce debate.

Green argues it remains that way, in part, because that landmark decision took abortion laws out of the hands of legislators.

"Some European countries have much tougher laws against abortion than the U.S. does, and it's because those laws were decided through parliamentary means," he said.

"Here, it was a Supreme Court ruling, and because of that, there's no real way for lawmakers who are opposed to abortion to do anything about it. And so the opposition to it continues."

The debate may cost Michigan congressman Bart Stupak his political career.

Stupak, who had previously vowed to vote no to the bill, lead the delegation of pro-life Democrats who opted to support it when Obama agreed to issue the executive order maintaining the abortion funding ban.

His Republican opponent, Dan Benishek, was a nobody until Sunday night, when he made his Twitter debut. Benishek has since amassed a sea of Facebook fans and pledges of financial support from pro-lifers across the United States.

Stupak also faces a pro-choice Democratic primary challenger and will undoubtedly feel the heat from all sides as the mid-term elections approach in November.

He was unapologetic for his flip-flop on Tuesday, disputing assertions by pro-lifers that the executive order was essentially meaningless and simply served to allow Stupak to save face.

"Some people say this piece of paper isn't worth it, but I would remind them that in 2007 when George W. Bush signed the executive order to prevent stem-cell research these groups that are criticizing it, they applauded it, they welcomed it," he said in an interview on CBS.

"And now President Obama's going to sign an executive order once again protecting life and somehow it's not worth the paper it's written on. You can't have it both ways."

The ferocity of the abortion debate hit Stupak hard on Sunday, when he says he was called a "baby killer" in the House of Representatives by a Republican colleague. Randy Neugebauer, a congressman from Texas, has insisted he was referring to the bill, not Stupak.