Relatives of people who kill themselves will not face prosecution as long as they do not maliciously encourage them and assist only a "clear settled and informed wish" to commit suicide, the Director of Public Prosecutions said today.
Keir Starmer QC outlined guidance to make it easier for those helping someone commit assisted suicide to know if they will face prosecution.
Today's move comes after the Law Lords backed multiple sclerosis sufferer Debbie Purdy's call for a policy statement on whether people who help someone commit suicide should be prosecuted.
Mr Starmer said: "There are no guarantees against prosecution and it is my job to ensure that the most vulnerable people are protected while at the same time giving enough information to those people like Mrs Purdy who want to be able to make informed decisions about what actions they may choose to take."
He added: "Assisting suicide has been a criminal offence for nearly 50 years and my interim policy does nothing to change that."
More than 100 Britons have ended their lives at the Dignitas clinic in Switzerland, but, until now, friends or relatives who accompany them have not known if they will face prosecution.
Today's clarification is intended to make it much easier for people to know if they will be prosecuted or not.
Mr Starmer outlined 16 public interest factors in favour of prosecution and 13 factors against prosecution.
Some factors in favour of prosecution included that the victim was under 18 and did not ask personally on his or her own initiative for the assistance of the suspect.
Another factor in favour of prosecution was that a relative "persuaded, pressured or maliciously encouraged the victim to commit suicide".
Factors against prosecution included that the victim had a "clear, settled and informed wish to commit suicide" and that the victim "indicated unequivocally to the suspect that he or she wished to commit suicide".
Mr Starmer said the policy guidelines would become effective from today.
The medical profession will also be bound by the rules, he added.
Asked if the guidelines would result in an increase in people committing assisted suicide, he replied: "Only time will tell. It may do, it may not do."
He said: "Each case must be considered on its own facts and its own merits.
"Prosecutors must decide the importance of each public interest factor in the circumstances of each case and go on to make an overall assessment.
"I also want to make it perfectly clear that this policy does not in any way permit euthanasia.
"The taking of life by another person is murder or manslaughter, which are among the most serious criminal offences."
The Roman Catholic Archbishop of Cardiff, the Most Rev Peter Smith, said the Catholic bishops of England and Wales would be studying the draft guidance very carefully.
He said: "The comments made by the DPP in his article in the Daily Telegraph this morning provide helpful reassurance on two key points.
"First, he emphasises that the law has not changed - assisted suicide remains a criminal offence and the prosecution authorities have a duty to investigate each case.
"Second, he made clear that no-one can expect a guarantee of immunity from prosecution. These are important and necessary clarifications.
"What the DPP has been asked to do by the House of Lords is to give more specific guidance about the factors he will take into account in deciding whether or not to consent to a prosecution.
"I would not be seeking to argue that every criminal case should be prosecuted - there can indeed be a particular combination of circumstances which will justify in a specific case a decision not to prosecute in the public interest.
"But such decisions can only be made on a case-by-case basis, and what is imperative is that any general guidance does not obscure the bright line of the law, which must remain clear and evident to all.
"With this in mind, the Bishops' Conference will be studying the draft guidance very carefully and taking expert legal advice in preparing our own response to the consultation."
Asked if the policy would see an end to Britons travelling to clinics such as Dignitas, Mr Starmer said: "This policy applies to any act in England and Wales. It is not a policy designed only to cover those that travel abroad."
Speaking at the Crown Prosecution Service headquarters in central London, he also launched a 12-week consultation on the list of factors identified as part of today's guidelines.
Assisted suicide is still illegal and will remain so following today's guidelines.
Under current legislation, those who "aid, abet, counsel or procure" someone else's suicide can be prosecuted and jailed for up to 14 years.
Debbie Purdy, from Undercliffe, in Bradford, West Yorkshire, wanted to know what would happen to her Cuban husband, Omar Puente, if he helped her travel abroad to end her life.
She took her case to the highest court in the country after the High Court and Court of Appeal held that it was for Parliament, not the courts, to change the law.
The Law Lords agreed that changes were a matter for Parliament but upheld Ms Purdy's argument that the DPP should put in writing the factors he regarded as relevant in deciding whether or not to prosecute.
Speaking from her home, Ms Purdy welcomed the new clarifications.
She said: "They seem great because it gives confidence to people like me that we cannot make a decision immediately and he actually says that he wants people to have explored alternatives, that he wants to make sure that other forms of treatment have been considered before this decision is made."
Ms Purdy, who was diagnosed with MS in 1995, said she was not asking for "an organisation in this country which encourages people to end their lives" but simply for the clarification of the law so she and her husband would know if he would be prosecuted if he helped her.
She said having such a clarification would allow people to leave it longer before making a decision to end their lives.
"We believe that us dying is very much a last measure and it shouldn't be considered a casual choice and I think these guidelines put in place, they codify, that people should consider alternatives but that if those things are considered and somebody assists them, they won't necessarily be prosecuted and that they will know what they must have done, they will know what they should make sure of before they assist.
"And that will hopefully give people confidence not to make such a decision until the last possible minute," she said.
Ms Purdy said the judiciary showed "courage" to look into the issues surrounding the law of assisted suicide, while politicians were "terrified of taking up the issue".
"The judiciary has had the courage to at least consider in the 21st century what are things that matter, and they are differentiating very clearly between malicious encouragement of people to end their lives and support for somebody who has made the considered and informed decision, which maybe can make them leave it longer to end their life."
Speaking about the situation faced by herself and her Cuban husband, Ms Purdy added: "We want to live our lives, not plan my death, and we can't do that while there is a huge cloud hanging over us that if I don't make a decision while physically able to do it myself, he could face prosecution.
"And now the DPP has put in black and white and is opening up for discussion with the public under what conditions people should or shouldn't be prosecuted."
Ms Purdy said there were some concerns in the guidance but she hoped these would be addressed during the consultation.
Asked whether Prime Minister Gordon Brown was comfortable with the guidelines, a Downing Street spokeswoman said: "The DPP was obliged by law to publish the new interim guidance.
"We will need to look at the detail in full and it will be consulted on.
"It is the case, and it remains the case, that the Crown Prosecution Service will look at each individual (case) and make a decision on prosecution based on the details of the case."
Shadow justice secretary Dominic Grieve said: "The Director of Public Prosecutions was required by the House of Lords to issue new guidelines. They do not appear to have altered the law, as it was previously understood.
"Assisted suicide cases raise difficult issues, and it must remain for Parliament to determine the right balance in the law."
Today's guidelines will not clear the way for Dignitas-style clinics to be set up in the UK as assisted suicide is still illegal.
Mr Starmer said: "The policy makes a distinction between, on the one hand, relatives, close family members and friends who, as a one-off and on a compassionate basis, may assist in a suicide, and, on the other hand, those that, on an ongoing basis, provide either a service or a business.
"Those in the latter category are more likely to be prosecuted because the factors in favour of prosecution would apply more to them."
He added: "The rationale behind that is that, for so long as Parliament retains the offence of assisted suicide in its current form, it is not appropriate for a prosecutor to indicate that somebody can provide an ongoing service or business to assist suicide because it is unlawful to do so."Reuse content