Rishi Sunak is being investigated by Parliament’s standards watchdog after he failed to tell MPs his wife owned shares in a childcare firm boosted by the Budget.

The Parliamentary Commissioner for Standards, Daniel Greenberg, is probing whether the PM broke the MPs’ code of conduct.

Mr Greenberg’s investigation, which was launched on Thursday last week and confirmed today, centres around shares Akshata Murthy holds in agency Koru Kids.

The company’s website said on its website that the new incentives open to childminders – announced by Chancellor Jeremy Hunt last month – are “great”.

The Mirror previously reported that Mr Sunak failed to mention Ms Murthy’s links to the company when he was questioned by MPs over why the private firms were set to benefit the most.

Downing Street has claimed rules were followed “to the letter”, but critics said there are “serious questions” over benefits his family could get from Government actions.

Lib Dem Chief Whip Wendy Chamberlain MP said: “Another day and another accusation of a Conservative Prime Minister bending the rules.”

She added: “After months of Conservative sleaze and scandal, the public just want a government which is focused on the country, rather than saving their own skin.”

Appearing before the Liaison Committee on March 28, Mr Sunak did not mention Ms Murthy’s shares in the firm, in which she has been listed as a shareholder on Companies House.

A fortnight earlier, Mr Hunt announced a pilot of incentive payments of £600 for childminders joining the profession.

Questioning why the sum doubles to £1,200 if workers sign up through an agency, Labour MP Catherine McKinnell asked if Mr Sunak had any interests to declare.

“No, all my disclosures are declared in the normal way,” Mr Sunak said.

An update to the parliamentary website shows the investigation concerns paragraph six of the MPs’ code of conduct.