Stefano Oliva said the unnamed woman wanted a “second chance” to prove she could care for the baby girl with the support of her family.
The Italian woman, who suffers from bipolar disorder, is reported to have gone to Britain whilst pregnant to attend a training course with an airline at Stansted Airport in Essex.
After she stopped taking medication, she had a panic attack and was sectioned under the Mental Health Act.
The Court of Protection took the unusual step of giving a health trust permission for doctors to carry out a caesarean section in August last year, and the newborn child was taken into care by Essex social services.
Mr Oliva said the mother was permitted to see her baby once a week until the end of October, when she moved back to Italy to get support from her family.
After returning to her home country she came back to Britain once a month to visit the child. This arrangement stood until May this year when social workers told her it would be the last time she would see her daughter, he said.
In February, Judge Newton, sitting at Chelmsford County Court, ruled that although the mother’s condition had improved and she was “extremely well” when she gave evidence, adoption was the best way to provide “a permanent, predictable and stable home” for the baby. The council had argued adoption was “the only safe route”.
The case drew wide publicity, even though it was heard in private. The president of the Family Division, James Munby, has ordered that any further applications relating to the baby, known only as P, must be transferred to the High Court.
“I do not understand why my client has been forced to have a caesarean section. It is a very unusual statement to be issued by a judge,” Mr Oliva told BBC Radio 5 Live. “From my point of view this decision is absolutely unreasonable.”
The lawyer told presenter Victoria Derbyshire: ““This woman has only a minor mental disease, which can be cured with medicine. She is not a woman who is not able to understand what is happening around her.”
Mr Oliva said the mother, who has two other children who live with their grandmother in Italy, is “clear and strong” adding: “She has a job, she has a house, she has a normal life, so there is really no reason why someone can force her to have a baby in one way or in another way.”
He said she came off her medication because she felt that she had been cured.
“This is why she had a panic attack, because she had stopped taking her medicine thinking she was okay,” he said. “Now this lady is absolutely under control. The baby has not yet been formally adopted by anybody so there is absolutely no reason why this woman should not be allowed a second chance.”
He said the woman pleaded with Judge Newton to be given a chance to prove herself. The woman was 34 weeks pregnant when medics performed the C-section on her, he said.
“One day someone took her to another unit and sedated her and forced her to have a baby,” he said.
Had they not performed the operation she would have gone home to Italy where she would have given birth to the baby girl naturally, Mr Oliva added.
He said the woman “understands” she has some problems. Her other two children were put in the custody of her mother by Italian social workers, but she sees them on a regular basis, he said.
The woman wants to move to America with all three of her children to live with a relative in America.
“She thinks she has to have a second chance,” he added. “My client would be glad to make the judge and social workers understand that she is not claiming to have the babies by herself, she is claiming to have the babies with the protection of the wider family, and she is imagining a better future for herself but mostly for all of her three children in the US.”
He said the woman had previously been told that her baby had been adopted and there was “nothing more she could do”, but he understands this is not the case.
Yesterday the woman told an Italian newspaper she had been left traumatised by the incident, adding: “I want my daughter back. I’m suffering like an animal.”
Mental health campaigners expressed concerns that the woman was not given sufficient time to show that she was fit to bring up her daughter.