Cameron put on spot over right-to-die law

The 46-year-old from Bradford, who suffers from multiple sclerosis, told the Conservative Party leader the current law on assisted dying "is not understood by people" and should be replaced with new legislation.

Ms Purdy said Britain needed a "proper legal framework" that would allow people wishing to end their lives to explore all options for help and support as well as assisted suicide – potentially saving lives as well as helping people die with dignity.

Mr Cameron, however, said he had real concerns over the implications of such a law, telling Ms Purdy the pair would have to "agree to disagree".

He said: "I admire your incredible courage and bravery in speaking out and taking your case to the highest courts of the land, but I just have this worry I can't get over.

"I think if you change the law further in favour of assisted dying, I worry you will have frail and elderly people who will be pushed and prodded into doing something they don't want to do.

"I'm very worried about creating a euthanasia society, which I don't want to live in. I had a friend who had motor neurone disease, and it does test to the core one's belief about euthanasia. Some of the degenerative conditions people have are truly horrific.

"I will go on reading, arguing and generally trying to get my head around this – but fundamentally I'm not in favour of approaches that take us closer to euthanasia."