MERSEYSIDE MP Claire Curtis-Thomas described how her paralysed mother had changed her mind about wanting to be left to die and to attack plans for people to draw up 'living wills'.
The Labour MP for Crosby revealed her personal experience to criticise a government Bill which would let patients - in advance - refuse treatment should they become mentally incapacitated.
David Lammy, the constitutional affairs minister, told MPs the Mental Capacity Bill would not introduce euthanasia by the back door, insisting it would remain a criminal act.
But, in an emotional speech, Ms Curtis-Thomas, described how her mother - an 'incredibly obstinate woman' - had reacted to a serious stroke that left her with no movement.
She had drawn up a legally-binding directive urging her family, in the event of another stroke, to do "everything you can to make sure I leave this world as quickly as possible".
Five years on, the MP's mother, Joyce Curtis-Thomas, did suffer a further stroke and Ms Curtis-Thomas attempted to get doctors to carry out the directive.
But several months passed before the MP was asked to decide whether her mother should be fed or allowed to starve to death, by which time she was "fully aware of what was going on".
Ms Curtis-Thomas described how, able to communicate through blinking, her mother made clear to her daughter and a nurse that she did not want to be starved.
She said: "I made sure she understood what I was saying and in the morning I went back to her and she blinked out 'I want to live'. There we have a legally-binding directive made following the most appalling stroke and, five years later, an individual who is struck down with the exact same condition saying 'I have changed my mind'.
"It would have been disastrous in the case of my mother - she would have died..
She didn't want to die, she wanted to live and she exercised the choice of changing her mind.
"It is almost impossible for us to know what we would be like under any given circumstances until those circumstances have arisen."
Ms Curtis-Thomas said her mother had lived for another five years following the second stroke, which had been "probably the best five years of her life in many ways".
She abstained on the second reading of the Bill on Monday night, in the hope the government would accept amendments proposed by the pro-life group of MPs.
Ms Curtis-Thomas added: "I don't think anybody in this chamber could agree to it if they had been with me on this particular journey."
MPs voted by 326 to 62 to give the Bill its second reading. It now enters its committee stage.