MPs will discuss scrapping Victorian abortion laws dating back to 1861 - which contain criminal sanctions for both women and doctors - in England and Wales.
Campaigners claim that under the current law vulnerable women such as rape survivors could end up facing lengthy prison sentences for buying illegal abortion pills online in order to terminate their pregnancies because they were too afraid to seek help from a clinic.
Former shadow health minister Diana Johnson will introduce her Reproductive Health (Access to Terminations) Bill in the Commons on Monday.
She said: "Removing the counter-productive threat of criminal punishment against vulnerable women will create an environment more conducive to reducing incidents of unplanned pregnancies and abortions - not least medically unsafe ones."
Diane Munday had an abortion in 1961, six years before the Abortion Act made it legal in Britain.
The mother of three says she just couldn't cope with a fourth child in four years after her contraception failed.
She was able to afford a Harley Street abortion with the backing of a psychiatrist, while others risked their lives in backstreet procedures at the time.
Five decades on, she says she's disappointed by the lack of progress in abortion laws and supports decriminalisation.
She told Sky News: "Little did I think that here we would be 50 years later, the only country in Europe, except the couple that outlaw it - Ireland and Malta, that has the strictest laws. We were the pioneers and it's ironic now we lag behind."
She supports further reform of abortion laws, adding: "Making abortion difficult or illegal doesn't make women having it, it makes them dangerous and it makes them unsafe."
Other countries, including Canada, have decriminalised abortion and the Royal College of Midwives and the British Pregnancy Advisory Service support the proposed changes.
Campaigners for the change say decriminalisation will not mean deregulation or make it easier to access abortion after 24 weeks - but these proposed changes are still controversial.
Anne Scanlan, education officer at pro-life charity Life, told Sky News: "I think we have to stop turning a blind eye to the fact that we are ending human life. I think this shows callous disregard, not just to the unborn child but for the health and safety of women."