Jailed British-Iranian Nazanin Zaghari-Ratcliffe is facing a new charge against her in Iran, her campaign says.
Her husband said the 39-year-old, who denied the new allegation of spreading propaganda, was told to expect a conviction by the judge.
The prime minister's spokesman said the government was urgently seeking more information from Iranian authorities.
Mrs Zaghari-Ratcliffe is serving a five-year jail sentence in Iran after being convicted of spying.
She was detained at an airport in April 2016 while travelling home with her daughter and was accused by Iran of plotting against the government.
Mrs Zaghari-Ratcliffe, from Hampstead, north London, denies the charges against her and says she was in the country to introduce her daughter, Gabriella, to her parents.
In her latest court appearance on Saturday, her husband Richard Ratcliffe said his wife asked the judge for leniency for the sake of her child.
According to The Free Nazanin Campaign, Mrs Zaghari-Ratcliffe said: "She hasn't seen her father for over two years now.
"I have been a good prisoner for the sake of my baby, and I would ask the judge to close this new case and give me parole - so that I can go home and have another baby and have a normal life."
Following her court appearance at the weekend, Mrs Zaghari-Ratcliffe was able to telephone the British ambassador to Iran for the first time in more than two years, her campaign said.
It added that she discussed, with both the judge and the ambassador, a request for her to be let out on temporary release for her daughter's fourth birthday next month.
The prime minister's official spokesman said: "The UK government remains committed to doing everything possible to help secure Ms Zaghari-Ratcliffe's release and alleviate her suffering."
The new charge came despite Theresa May raising her case, along with other British prisoners held in the country, with Iranian President Hassan Rouhani.
In a telephone call earlier this month, Mrs May had asked for them to be released on "humanitarian grounds".
Mr Ratcliffe has petitioned the UK government to help free his wife, making numerous media appearances and visiting Downing Street.
In November last year, Foreign Secretary Boris Johnson apologised for telling a Commons committee hearing that Mrs Zaghari-Ratcliffe had been teaching journalism in Iran - something her family and employer say is incorrect.
Mr Johnson raised the case with his Iranian counterpart in January and had been urged to do so again, by the family, when they met last week.