The little boy, known as Baby K, was removed by Nottingham City Council social workers without a court order only hours after being born at the end of January.

The council's barrister, David Lock, told the High Court in Liverpool: "I am entirely happy to accept that, on behalf of the local authority, it did not have an agreement from the claimant sufficient to be consent in law."

The day after her baby was taken the mother - known only as G - was reunited with him after an emergency High Court ruling that "on the face of it" he was removed without authority. But within days Nottingham City Council placed K with a foster family after a judge at Nottingham County Court granted an interim care order.

Before both sides agreed to compromise, the council planned to argue that G - who had a troubled childhood and mental health problems - had not objected to her baby being removed.

Just because she did not object did not mean she consented, said the judge, Mr Justice Munby. And the teenager's barrister, Ian Wise, countered the allegations and denied she had seen a "birth plan" setting out that K was to be removed.

He said: "She never saw the birth plan before the birth of the baby and was unaware of any proposal for an interim care order and never consented to the removal.

"At the time of removal there was uproar from the mother and her family so there certainly wasn't any consent at a prior stage or time when removal was given effect."

As well as admitting the authority acted unlawfully, it admitted that G - who cannot be identified for legal reasons - was not given proper care.

She should have been given an independent "personal adviser" to help make plans for her future. But the court heard that the girl's adviser also worked for the council and "had feet in both camps".