Guy Opperman said he realised people deserve "the death of your choice" after undergoing surgery to remove a tumour.
The minister for roads and local transport said: "Many in my NHS ward did not make it. Many died a long and painful death.
"If I were not one of the lucky ones post-surgery, I would have wanted to end my life on my terms." The MP for Hexham began suffering from fatigue and headaches months after his election in 2010.
Writing in support the Express Give Us Our Last Rights crusade today, he recalls being rushed to hospital after collapsing in Parliament.
Mr Opperman, 58, was among 118 MPs who voted in favour of the last assisted dying bill to reach the Commons in 2015.
He expressed "disappointment and anger" after it was defeated.
The MP said: "I believe in the life of your choice. And the death of your choice.
"I am a one-nation Conservative, and a former senior crown prosecutor. But I do seek the major change that is legislation for assisted dying."
Mr Opperman believes in palliative care and feels his Christian faith is important.
He wants strict safeguards but added: "We would never let our pets suffer as we insist that some humans suffer in their final days."
Mr Opperman spoke out ahead of Monday's historic Westminster Hall debate on assisted dying.
It follows a Daily Express petition backed by Dame Esther Rantzen and signed by 200,000 people.
The TV presenter, 83, who has stage four lung cancer, said the debate could "spread public awareness of this crucial life and death issue". She added: "While, sadly, my health issues prevent me from attending, I will be watching the debate closely as it affects my own decision to go to Dignitas in Zurich if necessary, to protect my family from witnessing a painful death.
"I know palliative care can be wonderful but it cannot guarantee the dignified, pain-free death we terminally ill patients all hope for."
The Childline founder is aware her family risk prosecution if they accompany her to the Swiss clinic.
She added: "This is not right, it is not ethical, and as it is my life, I, like the majority of the public, believe it should be my choice.
"Please support the campaign for parliamentary time and a free vote on assisted dying, so that we have the opportunity to change our current cruel, outdated law."