"We have seen over the last 20 years a general migration of positivity towards this being a just cause," Ted Goodwin, the American president of the World Federation of Right-to-Die Societies, told a news conference in Zurich on Tuesday.

Goodwin was speaking as representatives of 55 right-to-die societies from around the world gathered for a three-day congress to mark the 30th anniversary of Exit, a Swiss group which provides lethal drugs to help the terminally ill die.

Assisted suicide has been legal in Switzerland since 1942, if performed by a non-physician who has no direct interest in the death. Euthanasia, or "mercy killing", is legal only in the Netherlands, Luxembourg, Belgium, and the U.S. state of Oregon.

Goodwin said the election of Socialist Francois Hollande as French president could help the euthanasia cause in Europe. Hollande has said he favors euthanasia under strict conditions.

"If France falls into line, I believe Germany will also adopt it. That is a game changer in Europe," he said, noting support for reform was also gaining traction in Australia and Massachusetts. "Things are happening slowly but surely."

He said ageing societies meant that half of medical costs are now falling in the last three to six months of life on care that does not change the trajectory of a disease.

The number of Swiss residents who died by assisted suicide rose sevenfold between 1998 and 2009 to almost 300, statistics published for the first time showed in March.

"BURDEN FOR SOCIETY"

The Euthanasia Prevention Coalition is organizing an alternative conference on Friday to coincide with the public part of the Right-to-Die gathering in Zurich.

"Together with the increasing cost pressure in the health sector and the increasing loneliness of older people, organized assistance for suicide is a breeding ground which promotes suicide," Roland Graf, a priest who is vice-president for Human Life International Switzerland, told a separate news conference.

"The pressure is growing on people who can no longer give to society what is expected of them. They increasingly feel themselves as a burden for society and their relatives."

A rise in terminally ill foreigners - particularly from Germany, France and Britain - travelling to Switzerland to commit suicide have prompted calls in recent years for the country to tighten its liberal laws.

But in 2010, voters in Zurich overwhelmingly rejected proposed bans on assisted suicide and "suicide tourism", and in 2011, the national government decided against imposing new limits on assisted suicide.

Goodwin said the examples of Switzerland, Netherlands, Belgium and Oregon had not shown any noteworthy abuse.

"Ours is a mission of compassion, of generosity. We know that no-one is more vulnerable than those who are dying and those dying in pain," he said. "Society can provide protection for vulnerable individuals."

Exit President Saskia Frei said the practice was carefully monitored by the Swiss authorities: "There is no death which is as closely investigated as assisted suicide," she said.

Yet Alex Schadenberg, the executive director of the Euthanasia Prevention Coalition, pointed to studies from the Netherlands and Belgium which he said showed significant numbers of deaths by euthanasia "without explicit request or consent".

"The problem with euthanasia or assisted suicide is you're giving somebody else the right to be involved in causing your death," he said.

"Society needs to be vigilant about suffering, but the answer is not giving power over life and death to somebody else."

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