LONDON, Oct 2, 2008 (AFP) - A British woman who suffers from multiple sclerosis launched a legal challenge in Britain Thursday over whether her husband could be prosecuted if he helps her to commit suicide.

Wheelchair-bound Debbie Purdy, 45, has asked the High Court in London to clarify the law on assisted suicide as her health is rapidly deteriorating.

Her lawyer David Pannick told two judges: 'Her wish is to be able to ask for and receive assistance to end her life should living it become unbearable for her.'

The assistance might involve helping her to travel to Switzerland or Belgium, where assisted suicide is lawful, the court heard at the start of the two-day hearing attended by Purdy and her husband, Cuban jazz violinist Omar Puente.

Pannick said: 'Her dilemma is that she wants to delay her suicide as long as possible. She wants also to avoid the danger of her husband being prosecuted for assisting her.'

If Purdy's husband was likely to be prosecuted 'then she is much more likely to travel abroad to commit suicide sooner rather than later,' the lawyer said.

Pannick accused the authorities of breaching Purdy's rights under the European Convention on Human Rights by failing to publish a policy making clear the circumstances in which a prosecution would be allowed to proceed.

Before the debilitating disease took hold, Purdy enjoyed an adventurous life, parachuting and trekking through jungles.

She said she plans 'to live forever', but if her condition becomes unbearable she wants to decide when she dies.

She has joined Dignitas, the Swiss organisation which operates clinics where people can go to commit suicide.

Her ability to carry out everyday tasks is rapidly diminishing, and she now lacks the strength to propel an ordinary wheelchair and has to use an electrically-operated model.

Before entering court with her husband, Purdy said: 'What we want to do is live. We want to argue and fight -- be a normal couple.

'We don't want to have to go on worrying about what will happen in the future.'

Prosecution lawyers say the law does not require it to make a specific policy of the kind sought by Purdy.

They argue that legislation governing suicide dating from 1961, which makes aiding and abetting suicide punishable by up to 14 years in prison, in addition to existing special guidelines for state prosecutors, are sufficient.