PRIME Minister Theresa May has been urged to apologise "on behalf of the nation" to the hundreds of thousands of women who were pressured into handing over babies for adoption half a century ago.

More than half a million children were given up for adoption at a time when unmarried mothers were often rejected by their families and ostracised by society.

Wirral South MP Alison McGovern fought back tears as she recounted how women had lived under a "culture of terror and shame" to maintain some idea of societal respectability.

The Labour MP, whose voice cracked throughout her Commons speech, referenced the story of former Labour health minister Ann Keen who herself had been a victim.

She explained that Ms Keen, who served in government under Gordon Brown, fell pregnant as a teenager.

She said: "Her family were horrified and decisions were taken that she would move away where she would meet with a local moral welfare worker, and that's what social workers used to be called, and it was just assumed that the baby would be adopted.

"This moral welfare worker told Ann the baby would cause her family hardship. She was told if she loved the baby she would give it away, she was told it was for the best."

Adoptions were generally handled through agencies run by the Church of England, the Roman Catholic church and the Salvation Army.

Ms McGovern added: "There is one consistent impression, it seems obvious that those in a position of power, who the women came in contact with, felt that they ought to be punished.

"It's almost like there is some unwritten policy that women aren't to be treated properly and I think we owe it to that generation of women to ask ourselves who decided that they should be treated in this way."

Ms McGovern called on the Government to apologise "on behalf of the nation" and also requested the Government release any papers it has on the practice.

She said: "We can never re-legislate for the past but we must try and understand it and these policies were designed to make a so-called problem go away, society had decided that something that was entirely natural was shameful.

"Women and children were hidden away to protect the fragile sensibilities of others and it was a great injustice and then that culture of terror and shame has made them keep quiet for far too long.

"We've been told about this generation of mums, that she gave the baby up, a phrase that undoubtedly implies consent when actually that was never true."

Last August, the Government rejected a call for a public inquiry into forced adoptions, saying there was insufficient justification for it.

Shadow children and families minister Emma Lewell-Buck said an apology would allow those affected to "show the lifelong impact of unexpressed grief for unacknowledged loss."

Mrs Lewell-Buck added: "The very least they deserve is an apology."

Education Minister Nadhim Zahawi, responding to the debate, said the Government accepted that the legislation at the time was "not robust enough" as he expressed his deep regret at the practice.

But he said: "Adoptions during this period were generally handled through agencies run by the Church of England and the Roman Catholic Church and the Salvation Army. They have quite rightly apologised for their involvement in past poor practice."

Mr Zahawi also said it was "unlikely" that a public inquiry would uncover new facts.

"We believe that the lessons of the time have been learnt and have led to significant change to legislation and practice now - no child is removed from their birth family unless they have suffered significant harm or are at risk of such harm."

He added: "This House rightly acknowledges that this appalling historic practice has left a legacy of hurt and pain.

"I hope where possible many a mother and child can be reunited and be given the comfort of building a family relationship."

The motion was approved unopposed.