DUBLIN, May 20 (Reuter) - Police said on Tuesday they were investigating new claims that abortions were carried out at a Dublin clinic in defiance of Ireland's constitution, stoking the abortion debate ahead of Ireland's June 6 election.

Two women have made a complaint about illegal abortions at the central Dublin clinic, police said. They were already probing a claim by a woman in February that she was given a pregnancy termination in the clinic.

A spokesman for the clinic said the doctor at the centre of the allegations denied the claims but would not work there again.

A 1992 referendum upheld abortion's illegal status under the constitution but a Supreme Court decision allowed abortion if a woman's life is threatened by her pregnancy.

Laws have also been established to allow doctors to refer women to clinics overseas for abortions.

The debate has become an election issue after the main opposition Fianna Fail party pledged to hold a referendum on the Supreme Court ruling.

Anti-abortionists have been lobbying for a referendum to close all loopholes in the laws which forbid it.

But Prime Minister John Bruton rejected calls for a referendum in an interview published in the Irish Times on Tuesday. ``I don't see the point of having another constitutional referendum,'' he said.

Bruton said he was against abortion but believed the most effective way of preventing it was not by tinkering with the law.

``The most effective way we can reduce the rate of abortions is by counselling and support for women who have them so that they can take up the option of having their baby with the maximum support of the community,'' Bruton said.

``The human issue is saving lives as far as I'm concerned. It's not perfecting legal formulae.''