Britain's PM Sunak delivers a speech in London
Britain's Prime Minister Rishi Sunak delivers a speech on ending the "anti-maths mindset" to boost economic growth in London, April 17, 2023. Kirsty Wigglesworth/Pool via REUTERS Reuters

British Prime Minister Rishi Sunak is being investigated by parliament's standards watchdog over whether he properly declared his wife's shareholding in a childcare company which stands to benefit from new government policy.

Parliament's Commissioner for Standards began the investigation over a "declaration of interest" on April 13, according to a list of open inquiries on its website on Monday.

Opposition parties had raised questions over media reports that Sunak's wife Akshata Murthy was a shareholder in a company set to benefit from support for the childcare sector announced in March's budget.

"We are happy to assist the commissioner to clarify how this has been transparently declared as a ministerial interest," Sunak's spokesperson said, confirming the investigation was linked to the childcare firm.

The investigation is an embarrassment for Sunak, who came into office in October promising to lead a government with integrity "at every level" as he sought to revive his party's fortunes ahead of a national election expected next year.

Sunak and Murthy are the richest ever occupants of 10 Downing Street. Murthy is the daughter of one of the founders of Indian IT giant Infosys and owns about 0.9% of the company, worth nearly $600 million based on Monday's share price.

The couple faced criticism and public anger while Sunak was finance minister over Murthy's "non-domiciled" tax status which meant she did not pay tax in Britain on her earnings abroad. She subsequently gave up the status and said she would pay British tax on her global income.

The commissioner, who gave no details of the investigation, is responsible for the House of Commons code of conduct and investigates any alleged breaches.

Under the code of conduct, members of parliament have to provide information about financial interests which might reasonably be thought to influence their work in parliament.

If the investigation finds a breach, the Commissioner can require Sunak to apologise and set out steps to avoid any future errors, or refer him to a committee which has the power to suspend or expel him from parliament.

Opposition Labour Party deputy leader Angela Rayner said Sunak should publish an updated register of ministerial interests before municipal elections next month, saying the failure to do so had left "a transparency black hole which is enabling the prime minister and those he has appointed to dodge proper scrutiny of their affairs".

British Chancellor of the Exchequer Rishi Sunak and his wife Akshata Murthy attend a reception to celebrate the British Asian Trust at The British Museum
British Chancellor of the Exchequer Rishi Sunak and his wife Akshata Murthy attend a reception to celebrate the British Asian Trust, at The British Museum, in London, Britain, February 9, 2022. Tristan Fewings/Pool via REUTERS Reuters