The Bishop of Oxford has warned that plans to legalise assisted suicides sent a message to terminally ill people that their life had no value.

The Rt Rev Richard Harries spoke out in the House of Lords during a second reading debate on the legislation on May 6.

The bishop said he had profound sympathy for those in distress but argued that the proposal would have a seriously harmful effect on the vulnerable.

He said: "To change the law in this way would make elderly, sick and other vulnerable people even more vulnerable, and it would totally change the relationship between physician and patient."

The Bill, put forward by retired human rights lawyer Lord Joffe, and backed by a nurses' leader, would allow a competent adult to request medical assistance to die.

Under existing laws, people can be jailed for up to 14 years for aiding and abetting suicide. Lord Joffe claimed up to 26,000 patients a year were already being helped to die by their doctors.

The bishop believes that physician-assisted death is wrong and sends out a message to the patient that they are a burden.

He said: "The message they receive is that their life is no longer of value."

He said palliative care had improved hugely and the vast majority of patients could now spend the end of their lives free from pain.

He added: "A life that is dependent on others is not a wasted life. It is not a life without value or purpose."

Catholic bishops have urged peers to reject the proposals, claiming they would weaken protection for the sick and elderly and destroy trust between patients and doctors.

Lord Joffe said stringent safeguards were built into the Bill to protect the vulnerable.

It contains a conscientious objector clause to allow doctors who object to refuse to help a patient die.

A patient would first make a request for assistance to die and the doctor would discuss alternatives and make checks that the patient was not under pressure from someone else.

If the patient persisted, they would be referred to a psychiatrist and make a formal statement.

After the suicide, the doctor would document the process and send the records to a special monitoring body.