An assisted suicide campaigner has succeeded in her bid to force the Director of Public Prosecutions to issue guidance on the application of the law.
The ruling does not alter the law on assisted suicide but has nevertheless been welcomed by pro-euthanasia supporters.
Debbie Purdy, a former journalist, has had the support of euthanasia lobby group Dignity in Dying in her campaign demanding the guidance.
Miss Purdy has multiple sclerosis and says she may want her husband Omar Puente to help her travel overseas to kill herself when her condition worsens.
She claims that the current law is not clear enough for her to know whether or not Mr Puente is likely to face prosecution if he assists her suicide in this way.
The five Law Lords yesterday upheld her claim, and have now ordered the Director of Public Prosecutions (DPP) to produce specific guidance on the circumstances in which he would bring charges for assisting suicide.
In their judgment the Law Lords emphasised that only Parliament can change the law. Earlier this month an attempt to weaken it was rejected by the House of Lords.
However, the Law Lords said Miss Purdy had a human right to the information she was seeking, and ordered the DPP to come up with a “custom-built policy statement” explaining the various factors he would take into account before deciding to prosecute.
The DPP, Keir Starmer QC, said he had organised a team to come up with an interim policy on the matter over the summer.
After that, he said there would be a public consultation before a final policy was published in Spring 2010.
“In the absence of a legislative framework, cases of this sensitive nature present a significant challenge for prosecutors”, said Mr Starmer.
Supporters of the current law have described it as having “a stern face and a kind heart”, allowing the DPP to exercise discretion but also preventing abuse.
Lord Alton, a leading opponent of assisted suicide, said: “I think it would be highly regrettable were we to sleepwalk into having laws made by stealth in the courts.
“Compassion for Debbie Purdy should not cloud our judgment on the legal, ethical and medical issues posed by the legalisation of euthanasia.”
The campaign group Care Not Killing pointed to the Law Lords’ observation that the new policy statement will not provide Miss Purdy’s husband “with a guarantee of non-prosecution” if he helps his wife travel overseas.
The group said: “The Court has also recognised that it is Parliament’s responsibility to make the law and that this Judgment is designed simply to improve clarity in the way the law is administered.
“Parliament has recognised only three weeks ago, in its substantial rejection of Lord Falconer’s amendment to the Coroners and Justice Bill, that there are serious public safety implications involved in creating loopholes in the law to meet the wishes of a determined and strong-minded minority.”
More than 100 Britons have now died in the Dignitas suicide facility in Switzerland. The DPP has not yet prosecuted anyone connected with the deaths.
Following the defeat of Lord Falconer’s amendment earlier this month, two individuals have made high profile challenges to the authorities on the matter.
Alan Rees, who helped cancer sufferer Raymond Cutkelvin travel to Switzerland to kill himself was recently arrested after describing what he had done in an article for the Daily Mail in the run up to the Lords vote.
Earlier this week a doctor who was struck of the medical register for helping a patient commit suicide also challenged the authorities to take action after he admitted to giving Mr Rees and Mr Cutkelvin £1,500 towards the trip.