A Christian advocacy group is placing advertisements on London buses to reveal the “hidden reality” of abortion in Britain.

The campaign is being launched by Christian Concern to coincide with the 43rd anniversary of the passing of the Abortion Act next Wednesday.

The adverts feature the picture of an unborn baby and the words ‘Stop and Think’.

A survey last week revealed that most people have no idea that 200,000 abortions were carried out in Britain last year.

In the ComRes survey of 1,000 adults, just 3% correctly guessed that the number of abortions taking place in Britain each year was between 150,000 and 250,000.

Thirty per cent of people said they thought fewer than 20,000 abortions were taking place, a figure which rose to 45% in the 18 to 24 age group. One in ten said they thought between 20,000 and 50,000.

Christians will take part in a prayer vigil outside Parliament on Wednesday and a ‘Service of Lament’ in Westminster Abbey, at which the former Bishop of Rochester the Rt Rev Michael Nazir-Ali will speak.

Andrea Minichiello Williams, Director of Christian Concern, said the survey revealed a “widespread ignorance” of the scale of abortion in Britain.

She said the adverts would give people an opportunity to “stop and think about the wide-ranging implications of an act that has affected so many families in this country”.

“For too long abortion has been a taboo subject, a situation that only compounds the problems that abortion brings,” she said.

“It is time for society to face up to the hidden scale and consequences of abortion.”