By Jane Elliott Health reporter, BBC News

Julie Walters plays Dr Turner

The retired doctor had a degenerative neurological condition called progressive supranuclear palsy (PSP).

She knew she faced a slow death, becoming less and less able to communicate with her carers and loved ones.

This weekend her story 'A short stay in Switzerland' is brought to the small screen by award winning writer Frank McGuiness and starring Julie Walters, as Anne.

Assisted suicide

Writer Frank McGuinness said: "As a doctor Anne Turner lived and worked by her principles, and she chose to die by them. This film recognises that rare courage."

Julie Walters said taking on the role had been a challenge.

"I felt a great deal of responsibility to get the character of Anne right. But the script was fantastic and her personality just jumped off the page. Anne was clearly a remarkable woman who was determined not to be a victim."

Dr Turner's son, Edward, said his mother had been determined to die, but that because of UK law had been unable to do so at home. He and his family are now campaigning for a change in the law to allow physician-assisted suicide in the UK.

But he stressed the programme was not a polemic for assisted suicide and that he hoped that it would be watched by people with a broad spectrum of beliefs, allowing them to make up their own minds while exploring the concept of death.

I hope it will help people talk about death Edward Turner The BBC's Fergus Walsh recounts his nerve-wracking role

"If you were writing a polemic you would not chose all the details of this story," he said.

"Our mother was relatively able-bodied when she went off to Switzerland and would never have been able to have an assisted death in the UK. Also the final death scene was not easy.

"She was choking a bit because the barbiturates went down the wrong way.

"It is not a really peaceful ending. "It is traumatic and difficult."

But he said: "The audience will make up their own mind whether assisted dying is right or wrong.

"It does show the desperation people have when faced with terrible symptoms. I hope it will help people talk about death. If we don't, we are going to condemn ourselves to bad deaths,

"My mum would be delighted that people are talking about the issue, but embarrassed that she had become a key figure in the debate about assisted dying."

Reluctant to help

Edward, a board member of the campaign group Dignity in Dying, which supports assisted suicide, said that as a doctor his mother had been very well aware of how her illness would progress and that having nursed her husband through a similar terminal condition she knew she wanted to end her own life.

"My immediate reaction was to say 'I am so sorry and of course you will have my full support'.

"Well that's what I said, but what I thought was that there was absolutely no way I was going to let my mother take her own life.

"She is the most precious thing to me and it is just not going to happen.

"But I do think PSP is one of the worst things you can get.

Dr Turner had a degenerative neurological condition

"I think when you look at what happens she would have lost the ability to move any muscle in her body.

"She would have just been lying in her bed waiting for death, but her brain would have been OK.

"It was incredibly difficult for the family because we are all selfish human beings and want the people we love to hang around as long as possible no matter what condition they are in, but the only person that benefits is us."

Suicide attempt

His sister Sophie said that it was their mum's attempted suicide in 2006 that convinced them that she was serious.

"I could not face her trying that again or trying something similar depending on how desperate she would get so we talked about Dignitas.

"I called them when she was unconscious and by the time she woke up I wanted her to have an alternative in place."

She said she hoped the film would give people a little taste of their experiences.

Dr Turner went to Switzerland to die

"I thought if people can just get a snapshot of what we went through then maybe it will help people understand a bit better why we supported our mother and what she went through, and what my father went through.

"We do everything throughout life to relieve suffering all the way through life and when it comes to neurological illnesses when you could end up with a fully functioning brain and a useless body.

"No amount of palliative care is going to relieve those symptoms, so I think that is why they should be given the option to die if they want to - and a lot of people don't want to.

"My mother's life was cut short because she was worried that she would not be well enough to leave the country that she left while she had some quality of life left.

"I think if she knew that at any stage she would have been able to go to her doctor and have the procedure in the UK that she would have held on for longer."

'A Short Stay in Switzerland' - is on Sunday 25th January, BBC1, 9pm. It will be shown in Scotland, the programme will be shown on BBC2 at 10pm the same day.