Leading judges have rejected a challenge brought by disability rights campaigners against the prosecution policy in assisted dying cases.
The campaigners accused Director of Public Prosecutions (DPP) Alison Saunders of amending her policy in a flawed and "whimsical" way.
Nikki and Merv Kenward, supported by the Christian Legal Centre, said the change in wording makes the prosecution of healthcare professionals in assisted suicide cases ''less likely''.
But Sir Brian Leveson, Mr Justice Wilkie and Mr Justice Cranston unanimously ruled at London's High Court the legal challenge lacked merit and refused to quash the amendment.
The Suicide Act 1961 makes it a criminal offence to assist or encourage suicide.
The DPP has discretion on whether to prosecute according to the published policy.
Paul Diamond, appearing on behalf of the Kenwards at a recent hearing, argued that the amendment made last October represented a "substantive change" to the policy and made it more ''liberal'' - without the medical profession and other interested parties being properly consulted.
Mr Diamond referred to "the whimsical nature in which the policy has been amended" and the failure of the Attorney General to "superintend" the DPP on behalf of the Government.
Dismissing the application for judicial review, Sir Brian said: "The policy does not remove bright lines where previously they existed and no assistance or encouragement is rendered lawful that was previously unlawful."
The judge said the gradation between circumstances in which it would be appropriate to prosecute in an assisted dying case and those in which it was not would always involve "a very detailed consideration of all the facts and, ultimately, a balanced judgment".
The policy did not impact "on the view which professional regulatory bodies are entitled to take about the obligations and responsibilities of those whom they regulate".
The judge added: "The criminal law identifies minimum standards of behaviour, and professional requirements may well be set at a higher level.
"Thus, although I recognise that Mr and Mrs Kenward hold very strong views, I do not accept this policy provides support for the proposition that those views will not be respected by all with whom they come into contact."
Mrs Kenward, from Aston on Clun, Shropshire, is a former theatre manager confined by illness to a wheelchair.
She and her husband campaign against euthanasia and assisted suicide through the Distant Voices group.
She has said of the amendment: "If it is not removed, and this becomes the law, it will change how we view death. It will create a new means whereby euthanasia is an accepted form of behaviour."
But a man with locked-in syndrome who wishes to be able to end his own life intervened in the legal action to back the DPP.
Referred to as "AM", or Martin, his lawyers argued the amendment to the policy was properly made and the application for judicial review should be refused.