A woman with multiple sclerosis has won the right to mount a challenge in the High Court to force the country's top prosecutor to clarify the law on assisted suicide.

Debbie Purdy, from Bradford, is seeking assurances so that she does not have to worry about her husband if he helps her visit a euthanasia facility in Switzerland at some stage in the future.

The law states that assisted suicide is a crime that carries a maximum sentence of 14 years prison, but since 1992 almost 100 British citizens have ended their lives at the Dignitas facility in Switzerland - where assisted suicide is legal - without their relatives being prosecuted.

However, Purdy fears that her professional musician husband Omar will be treated more harshly because he is Cuban. She wants the Director of Public Prosecutions to clarify the law to set her fears at rest.

At a brief High Court hearing, two of the country's top judges, Lord Justice David Latham and Justice Robert Nelson, gave the green light for a full hearing in the case.

"The case needs little introduction," said Purdy's lawyer, Paul Bowen.

"It concerns the question whether a person such as Mrs Purdy who suffers from a terminal illness may be assisted by her husband to travel abroad to take advantage of the different laws in countries such as Switzerland where assisted suicide is not a criminal offence."

He argued that the European Court of Human Rights in Strasbourg has already ruled that this is a right which may fall within the scope of the European Convention on Human Rights.

He added the High Court did not have to follow the ruling of Britain's highest court, the House of Lords, in a similar case brought by motor neurone disease sufferer Diane Pretty, that the European Convention did not cover the issue.

Seven years ago, Pretty failed to secure immunity from prosecution for her husband if he helped her to die in the UK. She died aged 43 in 2002.

Purdy's case is expected to reach court after October this year.