More than a thousand Britons would kill themselves each year by doctor-assisted suicide if a controversial US law is imported to Britain, a think tank has told MPs and peers.

Safeguards to limit the law to only those patients who are terminally ill will also become meaningless, a new report says, as some doctors began to interpret the rules liberally in practice.

The report by Living and Dying Well says that in Oregon, the first US state to legalise assisted suicide, this has led to “doctor-shopping” for physicians who will overlook criteria that say candidates must be terminally ill, mentally competent and making a choice to die free from coercion.