As MPs prepare to consider legalising assisted suicide, the Archbishop of Canterbury has warned of a "slippery slope". 

Archbishop Justin Welby was speaking ahead of Labour MP Kim Leadbeater's private members' bill being formally introduced to the House of Commons Wednesday. 

"I think this approach is both dangerous and sets us in a direction which is even more dangerous, and in every other place where it's been done, has led to a slippery slope," he told the BBC. 

Assisted suicide is legal in the Netherlands, Belgium, Canada, Switzerland, New Zealand, Australia and 11 US states. 

Opponents of legalising assisted suicide point to examples like Canada where restrictions have been relaxed over the years from terminal illness to including serious or chronic health conditions that are not life threatening, and plans to expand the laws again to include mental health conditions. Both Belgium and the Netherlands allow assisted suicide for minors. 

The Archbishop spoke of his decades of experience as a priest sitting with people wishing their sick loved ones would pass so that their suffering would end. He said he did not want people to feel guilty for feeling that way and admitted to having similar thoughts as a teenager when his own father was ill. But he warned against harmful consequences of changing the law. 

Recalling his own mother's feelings of being a "burden" before she passed away last year at the age of 93, he shared his fear that others might feel pressured into asking for assisted suicide.

"What I'm saying is that introducing this legislation opens the way to it broadening out such that people who are not in that situation [terminally ill] asking for this, or feeling pressured to ask for it," he said.

Leadbeater has claimed that Britain has a "moral obligation" to change the law. 

"There would be two doctors involved in this process and a High Court judge as well, so there would be layers and layers of protections ...," she told LBC.

"If we get this right from the start we are giving people the choice I believe they deserve but it will be a very robust piece of legislation."

Supporters include the former Archbishop of Canterbury, Lord George Carey, and Dame Esther Rantzen.

Lord Carey is not representative of most Anglicans on the matter. In 2022, when it was last debated in the Church of England's parliamentary body, the General Synod, only 7% supported legalising assisted suicide. 

A survey of 1,185 Church of England priests by The Times newspaper last year found that while support for a change to the law has increased, a majority (54.9%) are still opposed. 

A survey of 10,000 people by Opinium on behalf of Dignity in Dying earlier this year found that three quarters back the legalisation of assisted suicide. Only 14% were opposed.

An analysis by i newspaper of 312 MPs who have publicly stated their view found that over half (54%) are in favour of changing the law.