CANBERRA, Sept 18 (AFP) - The Dalai Lama boosted the spirits of supporters of legalised euthanasia here Wednesday, saying mercy killing was permissable in certain exceptional circumstances under Buddhist philosophy.

Tibet's exiled spiritual figurehead and leader of eight million Tibetan Buddhists also said abortion would be permissable in certain cases such as when the life of a mother was threatened.

His comments followed an invitation during a lunchtime address to the National Press Club here to weigh into the debate still raging here over legalised voluntary euthanasia.

A federal MP has introduced a private member's bill in the National Parliament in Canberra to override the Northern Territory's world first voluntary euthanasia legislation which came into force on July 1. However, because of continuing legal efforts to overturn it, the Rights of the Terminally Ill Act has not been used so far as is known.

Asked his view on euthanasia, the Dalai Lama said Buddhists believed every life was precious and none more so than human life, adding: "I think it's better to avoid it."

"But at the same time I think with abortion, (which) Buddhism considers an act of killing ... the Buddhist way is to judge the right and wrong or the pros and cons."

He cited the case of a person in a coma with no possibility of recovery or a woman whose pregnancy threatened her life or that of the child or both where the harm caused by not taking action might be greater.

"These are, I think from the Buddhist viewpoint, exceptional cases," he said. So it's best to be judged on a case by case basis."

Pope John Paul II's recently confirmed the Roman Catholic Church's strict prohibition on mercy killings.