The rights of the woman, whose name had not been made public, were abused by family courts, British Member of Parliament John Hemming said.
The Liberal Democrat, who is chairman of the Public Family Law Reform Coordinating Campaign, said he plans to raise questions in Parliament this week about the extent of social workers' powers after the Italian woman was sedated and had her baby removed by surgery without her knowledge.
The woman was in Britain on business last year when she suffered a panic attack and called police, The Sunday Telegraph reported.
She was taken to a psychiatric hospital after it was revealed her symptoms were likely due to the woman not taking her medication for bipolar disorder, the newspaper said.
After five weeks in the hospital, she was sedated and when she woke up, her daughter had been removed from her womb. The woman said the procedure was done without her prior knowledge.
The 15-month-old girl is still in the care of social services in Britain, the Telegraph said. The newspaper said a judge has ruled the child should be put up for adoption because the mother could suffer a relapse.
"I have seen a number of cases of abuses of peoples' rights in the family courts, but this has to be one of the more extreme," Hemming was quoted as saying by the newspaper. "It involves the Court of Protection authorizing a Caesarean section without the person concerned being made aware of what was proposed. I worry about the way these decisions about a person's mental capacity are being taken without any apparent concern as to effect on the individual being affected."