A bill currently before the House of Lords proposing the legalisation of assisted suicide would be a “blank cheque” with regard to safeguards, according to three leading legal authorities.

The proposals, put forward by Lord Falconer, a former mentor of Tony Blair, have been criticised by Baroness Butler-Sloss, the former head of the High Court Family Division, Lord Carlile QC and Lord Brennan QC, who say there is a lack of protections for vulnerable people in the Bill.

Lord Falconer’s legislation, the Assisted Dying Bill would allow doctors to give lethal drugs to patients who are believed to have less than six months to live, the Daily Telegraph reports.

It had its first reading in the House of Lords in May earlier this year, and is yet to be scheduled for its second reading.

The three peers made their comments in a paper published by campaign group Living and Dying Well.  

They argue that a change in the law would make it legal for people to “involve themselves in deliberately bringing about the deaths of others”.

The Bill, they say, contains no protections for assessing assisted suicide requests, leaving the “real safeguards” to be decided after it has been approved.

The report said: “But knowing what the proposed safeguards are and assessing their effectiveness is an integral part of Parliament’s consideration of the bill.”

“As it stands, the bill is asking Parliament to sign a blank cheque.”

The peers also pointed out that no evidence has been produced to show that the current law is not fit for purpose.

The Peers said: “Licensing doctors to supply lethal drugs to some of their patients to facilitate their suicides would represent a major change to the criminal law.”

The Living and Dying Well group has previously warned that Lord Falconer’s Bill fails the public safety test and is “wholly inadequate”.

They said the Bill ignores medical evidence about how unreliable the prognoses for terminal illnesses are, yet places responsibility for assessing assisted suicide requests with the medical profession.

Supporters of Lord Falconer’s proposals said the new law is not about encouraging suicide.

A spokesperson for pro-euthanasia group Dignity in Dying said: “Those opposed to the assisted dying bill have every right to raise their concerns, but in doing so they also have a responsibility to explain why some dying people should have to suffer against their wishes.”