A woman with a long history of drug and alcohol misuse who has accepted that adoption is the best option for her six-year-old son has been described as "truly remarkable" by a High Court judge.

The woman told Mrs Justice Pauffley at a hearing in the Family Division of the High Court in London that she was unable to look after the little boy.

The judge said the woman, who is in her 30s, had "insight" into her problems and knew that she could not be the "kind of mother" her son needed.

"I would wish (the boy) to know that I am in no doubt at all about the extent of his mother's love for him," said Mrs Justice Pauffley, as she approved a local authority adoption plan.

"Everything she has done here she has done for (her son) precisely because she loves him and wants the very best for him."

The judge added: "She is a truly remarkable woman."

Detail of the case has emerged in a written ruling by the judge published on a legal website.

Neither the child nor the woman was identified.

But the judge said the local authority with responsibility for the boy's welfare is the London Borough of Newham.

Mrs Justice Pauffley said the woman had a "long history of drugs and alcohol misuse".

"She had indicated an acceptance that currently she is unable to look after him," said the judge.

"Sadly, at the present time, the mother is not at all well. She has depression for which she is receiving treatment and she suffers from occasional panic attacks.

"She described how this is not an easy time for her; she has been abusing alcohol and she does need help."

Mrs Justice Pauffley added: "The mother does believe she can improve her life and her prospects but she will need help."

The judge said the boy's father was deported in 2012 and lives and works abroad.