Labour is tabling an urgent question to parliament on the Briton held prisoner in an Iranian jail, Nazanin Zaghari-Ratcliffe, sources have told Sky News.
The Foreign Secretary Boris Johnson has been under sustained pressure after making comments that could prolong her sentence.
He told MPs the 38-year-old was in Iran to train journalists despite her family's claim she was in the country to visit relatives with her daughter.
Jeremy Corbyn attacked Mr Johnson for his comments, calling for the Foreign Secretary to be sacked for "putting our citizens at risk".
But her husband Richard Ratcliffe, who spoke to his wife over the weekend, says it would not be in her interests for Mr Johnson to go, as he is now fully aware of the need to work to win her freedom.
The wording of Labour's question is not yet known but it is thought, if it is approved by the Speaker, it will be answered by a junior minister in Mr Johnson's department after 2.30pm on Monday.
Mr Johnson, arriving for a meeting of foreign ministers in Brussels, said all consular cases "are all very sensitive" but the "key thing to understand" was that the Foreign Office was "working very hard intensively and impartially on all those cases".
Labour's shadow Brexit secretary Sir Keir Starmer told Sky News there was a "strong case" for Mr Johnson to be sacked and any strong Prime Minister would have done so before now, but he acknowledged Mrs Zaghari-Ratcliffe's family's "acutely difficult position".
Mrs Zaghari-Ratcliffe was arrested in April 2016, and jailed for five years amid claims she was working against the Iranian regime – a claim she denies.
Mr Johnson's comments have been widely reported by state media in Iran and held up as justification for her incarceration.
The Labour MP who represents the family's constituency, Tulip Siddiq, told Sky News that Mrs Zaghari-Ratcliffe was "inconsolable", "sobbing down the phone" to her husband and "couldn't believe (Mr Johnson) could make comments that would endanger her life".
Her family says her health is also increasingly precarious: that her mood is "uncontrollable", she feels "on the verge of a nervous breakdown" and that doctors have found new lumps in her breasts.
Mr Ratcliffe said his wife was taken to hospital for tests after complaining of "stabbing pains" in her breasts.
Lumps were discovered which a specialist said may be benign but she has been put under close surveillance as she has a family history of breast cancer and because the stress she is under could make her more at risk of developing the disease.
Sky News has been told that Mr Ratcliffe spoke to Mr Johnson on Sunday and, after the pair agreed to meet, asked whether his wife could be considered for diplomatic protection.
Mr Johnson is due to travel to Iran in the coming few weeks and is expected to raise the issue of Mrs Zaghari-Ratcliffe's imprisonment with the Iranian authorities.
With the help of Redress, the family has previously submitted a legal opinion to the Foreign Office, outlining her eligibility for diplomatic protection.
Critics say comments by Mr Johnson's Brexit Cabinet ally Michael Gove on Sunday, that he did not know why Mrs Zaghari-Ratcliffe was in Iran, have not helped her cause.
