The government ethics watchdog has been urged to investigate allegations Rishi Sunak breached the ministerial code of conduct by failing to declare his wife's financial interests worth hundreds of millions of pounds.
Labour MP Tonia Antoniazzi has written to the chair of the Committee on Standards in Public Life, Jonathan Evans, raising concerns about the shareholdings and directorships held by Akshata Murty and her family.
In her letter dated 30 November, shared with The Independent, she highlights that the code of conduct states that ministers should provide a list of interests of their spouse of partner and close family "which might be thought to give rise to a conflict".
Ms Antoniazzi adds: "The reports around the chancellor’s financial affairs are extremely concerning, and I am writing to ask you to assess whether this is a direct contravention of the Ministerial Code of Conduct.
"These reports follow your recent comments where you expressed “real concern” around the handling of high-profile allegations against senior ministers. Moreover, these allegations further erode public trust in politicians and bring parliamentarians into disrepute.
"As a matter of urgency, you must fully investigate these allegations and take all appropriate steps."
It comes after The Guardian reported that Ms Murty was "richer than the Queen" as a result of a £430m shareholding in Infosys, a technology company co-founded by her father. The newspaper also set out shareholdings in six other UK companies which have not been declared by the chancellor.
HM Treasury said Mr Sunak had made a full declaration of his wife’s interests to senior civil servants before a decision was taken on what to include in the list.
Boris Johnson's former adviser on minister's interests, Sir Alex Allan, was also satisfied, according to a spokesperson who said Mr Sunak “followed the ministerial code to the letter in his declaration of interests".
Sir Alex resigned earlier this month after the prime minister decided not to take action on his conclusion that home secretary Priti Patel had breached the ministerial code by bullying civil servants.
In September the Committee on Standards in Public Life said it was carrying out a review of the "institutions, processes and structures in place to support high standards of conduct".
Lord Evans said: "The committee is aware that public perceptions of standards remain low, as they have for many years in fact. We want to look at what is working well and what more needs to be done to support high standards of conduct across public life.”