Assisted suicide may be legal in Britain in as little as four years, a Tory MP has predicted.

Andrew Mitchell told Sky News there was growing support among MPs for a change to the law on assisted suicide.

He said his views on the issue had "changed completely" after being moved by the accounts of several constituents who saw their family members suffer at the end of their lives. 

Mitchell, who is co-chair of the all-party parliamentary group for choice at the end of life, said he was not looking for "massive change" in the law but "very, very tight reform". 

"I think that given the very limited nature of these proposals; that it would be for someone who is within six months of the end of their life, with very strong safeguards, the decision being made by a High Court judge, by two doctors - I think those limited proposals may command the support of parliament in the next four years," he said. 

At present, it is a criminal offence under the Suicide Act 1961 for a person to encourage or assist in the suicide of another. 

There have been numerous legal challenges to this law in recent years, all of which have failed. 

The most recent was that of Phil Newby, from Rutland in the East Midlands, who suffers from motor neurone disease.  The 43-year-old lost his High Court challenge, and in the Court of Appeal earlier this year. 

Disability activist Sian Vasey said lawmakers were right to be concerned about changing the law. 

"I would be very scared if a doctor said to me; 'Well, you know, would you like to consider ending your life?'" she told Sky News. 

"I think, quite honestly, it will extend massively and I think we are right to feel worried about it, and to be saying absolutely not.

"It's not a good thing for humanity really. It's a very discouraging idea that basically [you] go to the doctor and you can negotiate your death."

If you are feeling emotionally distressed or suicidal, the Samaritans UK can be contacted on 116 123 or by emailing jo@samaritans.org.