Hundreds of MPs will be receiving the postcard asking them to sign the pro-life pledge this week.
MPs will this week start receiving an avalanche of postcards from constituents demanding an end to abortion.
Thousands of voters are taking part in a coordinated campaign to mark the 50th anniversary of controversial legislation which has so far claimed the lives of almost 9 million unborn babies.
SPUC asked supporters to lobby MPs calling for an end to abortion in Britain.
Protest postcards have been sent to 532 MPs - more than 80 per cent of the 650 sitting in the House of Commons, and delivery began yesterday (Monday 30 Jan).
A clear message
SPUC spokeswoman Antonia Tully, said:
"The vast majority of MPs are receiving a clear message from their constituents that they want an end to abortion in Britain. Thousands of people are asking their MP to recognise the humanity of unborn babies and to work to give these defenceless human beings the legal protection they deserve.
"Each of the postcards which will flood the House of Commons has been signed by a person who is unhappy about abortion in this country."
Pro-Life Pledge
SPUC hope MPs will sign up to their Pro-Life Pledge indicating their willingness to help protect unborn children from abortion. Chief executive John Smeaton said:
"By doing this MPs will be showing that they care about the weakest most vulnerable members of society. And that they will to work to protect these very young lives from abortion.
"This is an important part of our campaign to mark the 50th anniversary of legalised abortion in this country.
"Tens of thousands of people from throughout the nation are deeply concerned about abortion and the devastating consequences it has on both unborn babies and their mothers.
"Since its inception, the Abortion Act has been responsible for the killing of more than 8.7 million unborn children.
"And in the wake of this legislation, thousands of women have been emotionally damaged and psychologically traumatised following procedures."
Abortion on an industrial scale
Mr Smeaton added:
"When the Abortion Act was passed 50 years ago many people presumed it was for a limited number of so-called 'hard cases'
"Yet, now, more than 4000 unborn babies lose their lives through abortion every week. This is the equivalent to the weekly loss of 20 passenger jets each carrying 200 passengers.
"Given these facts, it is clear that abortions in 2017 are being carried out on an industrial scale with 98%2 of those performed in this country carried out at the expense of the taxpayer through the NHS."
Scandal at Marie Stopes
Recent inspections by the Care Quality Commission of English clinics run by Marie Stopes International - which performs huge numbers of abortions on behalf of the NHS - found such serious safety concerns that services had to be suspended.
Mr Smeaton said:
"It is within this context so many people have signed our postcards. They want unborn children to have the same legal protection as any other citizen."