Rishi Sunak must “come clean” and publish his financial interests while under investigation over a possible failure to make a declaration to MPs, Sir Keir Starmer has demanded.

The Labour leader urged the Prime Minister not to “hide behind the process” and to make the details public to “clear this up” before the end of Tuesday.

Mr Sunak is facing an inquiry by Parliament’s standards watchdog amid claims he did not declare his wife’s shares in a childcare agency that benefited from the Budget.

Home Office minister Chris Philp insisted Mr Sunak has not done “anything sinister”.

Downing Street said Mr Sunak “transparently” declared the shares Akshata Murty holds in Koru Kids as a ministerial interest, rather than to the Commons.

But the register that would reveal whether any possible conflict of interest has been detailed has not been updated in nearly a year.

Speaking to broadcasters during a visit to York University, Sir Keir said the allegation is “obviously serious”.

“The Prime Minister promised integrity and accountability when he came into office so I think he needs to clear this up and declare his interests,” the Labour leader said.

“The register of ministerial interests hasn’t been published for nearly a year so I invite the Prime Minister to publish, at least, his entry on this issue today, clear this up, because he promised transparency.

“Don’t hide behind the process, just come clean and tell everybody what the interest is so people can see it and judge it. That’s what transparency is.”