Sir Keir Starmer has apologised on behalf of the British state for its role in historical forced adoptions in England and Wales.
An estimated 185,000 babies were taken from their mothers in the 1950s, 1960s and 1970s, with women pressured into giving up their children because they were unmarried.
In a statement in the House of Commons, Sir Keir said what happened to “tens of thousands of mothers, children and families” was “a stain on our history”.
“The shame is not yours. The shame was never yours. The shame is ours,” he said.
The apology comes after years of campaigning from mothers, adoptees and their wider families, and parliamentary reports into the issue.
No compensation scheme has been put in place, but a £4 million support package over three years has been announced for better access to adoption records and improved family reunion services.
Sir Keir said: “Mothers, many young, vulnerable, and without support were coerced, bullied, or misled into feeling that they had no choice but to have their children taken away from them. What a thing to do.”
Sir Keir said the forced adoptions were not isolated or accidental acts, but were practices “embedded” across local authorities, religious organisations and parts of what is now the NHS.
“All institutions that operated with power over people’s lives, yet they did so without compassion, without consent, and without dignity or proper safeguards” he told the Commons.
He continued: “We are deeply and profoundly sorry to the mothers who were told they were unfit, who were prevented from caring for the children they desperately wanted to help and to keep, and who have carried this loss for decades.”
During the prime minister’s speech, some of the birth mothers and adoptees watching from the public gallery were seen wiping away tears, while others clapped.
Conservative shadow minister Alex Burghart agreed with Sir Keir that historical forced adoption was “a stain on our history”, as he added former practices are “mercifully alien to us” today.
Speaking in the Commons, Burghart said: “those beliefs have left a permanent mark on each and every one of those lives, on children separated from their mothers and on the mothers whose children were taken away.”
Support groups for mothers and adopted adults will be established by the Department of Education, Sir Keir told the Commons.
Campaigners met the prime minister in Downing Street ahead of the apology.