Labour is trying to force the government to "come clean" and publish any advice given to the prime minister about reappointing Suella Braverman as home secretary.
Rishi Sunak brought her back into government six days after she resigned from Liz Truss's cabinet over breaking security rules and breaching the ministerial code.
Ms Braverman later revealed she had sent official documents to her personal device six times during her six weeks in office.
But she has denied reports she ignored legal advice over the handling of people who had made Channel crossings in small boats, or that she blocked asylum seekers from being moved into hotels when processing centres became overcrowded.
Further accusations have also surfaced that she was the subject of leak inquiries carried out by the Cabinet Office when she was attorney general.
Mr Sunak has stood by his appointment of Ms Braverman, saying she had acknowledged her mistakes and was welcome back on the frontbench.
But shadow home secretary Yvette Cooper is now putting forward a motion in the Commons to try to force the PM to share with parliament any relevant government security and risk assessments about Ms Braverman's alleged leaks and security breaches, and any information given to him before her reappointment.
Opening the debate, Ms Cooper said: "It is 15 days since the prime minister appointed his new cabinet, 14 days since it was reported that the prime minister was advised not to reappoint certain ministers, including the home secretary... on grounds of standards and on grounds of security.
"The prime minister promised us this would be a break from his predecessors, from the favour for mates culture... from the chaos... and instead the opposite has happened."
But Paymaster General Jeremy Quin attacked her for focusing on "rumour and speculation" rather than issues within her brief, such as immigration or policing.
"The home secretary [has] set out in considerable detail the circumstances and sequence of events that led to her resignation," he said. "She has explained that she made an error of judgement, she recognised her mistake and took accountability for her actions.
"The prime minister received assurances from [Ms Braverman] and he was clear that [she] had recognised her error and had accepted the consequences. He considered that the matter was closed.
"The prime minister was pleased to be able to bring the home secretary with her undoubted drive and commitment back into government and to be working with her to make our streets safer and to control our borders."
If passed, Labour's motion would be binding, but despite support from the opposition benches, the government majority makes that scenario unlikely.
However, it comes as Mr Sunak is under growing pressure over his judgement around another appointment to his cabinet - Sir Gavin Williamson, who has been accused of sending abusive texts to a former chief whip and bullying a senior civil servant.