In a referendum yesterday, 85% of the 278,000 votes cast opposed proposals to ban assisted suicide, while 78% opposed outlawing the practice for foreigners.

Around 200 people commit assisted suicide each year in Zurich, including many foreigners. The Zurich-based assisted suicide clinic Dignitas says it has helped 150 Britons to die.

The Evangelical People’s Party and the Federal Democratic Union had proposed limiting assisted suicide to people who had lived in Zurich for at least one year, a measure that would cut down on so-called “suicide tourism”.

The proposals were opposed by Switzerland’s two main parties, the Swiss People’s Party and the Social Democrats, who both called upon their supporters to resist changes to the country’s relaxed suicide laws.

Sarah Wootton, chief executive of pro-euthanasia group Dignity in Dying, said Zurich’s voters had made a “brave decision”.

“With the present lack of a safeguarded alternative at home, this result will come as a relief to many people in Britain who want the choice of an assisted death, should they find themselves suffering at the end of life,” she said.

“The people of Zurich have taken a brave decision, and in doing so they have refused to turn their backs on dying Britons who want the choice to end their suffering – nor should we.”

The Care Not Killing alliance of 40 pro-life organisations expressed its disappointment over the vote.

“We are disappointed that voters in Zurich appear to have followed the call of the two major political parties to support the status quo in today’s referendum on assisted suicide after an earlier poll showed that two thirds of Swiss people were concerned about suicide tourism,” said Dr Peter Saunders, Care Not Killing’s campaign director.

“However we are pleased that the Swiss government is still planning to revise the country’s federal laws on assisted suicide next year.”