Paul Hill is due to be executed by lethal injection for shooting dead the doctor, John Britton, and his driver, James Barrett, outside a clinic in Pensacola, Florida, in 1994. Hill, 49, has since become a hero of anti-abortion extremists.

There have been at least 10 attempts to kill doctors and others involved in abortion services in the US and Canada in the past decade, according to the National Abortion Federation. The most recent killing was in 1998 in Amherst, New York.

Last minute repentance from Hill, a former minister, is unlikely: he believes Jesus would have done what he did. "If I did not intervene and prevent the abortionist from entering the clinic ... he would likely kill thousands of unborn children," he wrote in an essay entitled "I shot an abortionist".

Pro-choice groups are bracing themselves for a backlash. "We expect the execution will trigger further violence," Vicki Saporta, president of the abortion federation, said. "We are extremely concerned about abortion providers being targeted for murder and extreme violence."

Moderate anti-abortion organisations have been anxious to distance themselves from Hill. "Paul Hill did our cause no favours," said Joe Sheidler of the Pro-Life Action League. "You don't kill abortionists. You try to convert them peacefully."

Others, however, have embraced him as a hero. Don Spitz is a defrocked Presbyterian minister attached to an underground anti-abortion network. "The state is murdering Paul Hill and I believe there will be far-reaching consequences," he said.

· President Bush has imposed a government ban on foreign aid to family planning organisations that use their own funds for abortion counselling.

The measure expands a directive issued two years ago that blocks the US Agency for International Development from funding groups that provide abortions, or provide information on abortion.

Family planning organisations said the ban reinforced last week's decision by the state department to withhold funding from a project for refugees with Aids in Africa. One of the seven agencies involved, Marie Stopes International, provides abortions.