Boris Johnson is being urged to explain how the refurbishment of his Downing Street flat was paid for, following allegations from his ex-chief advisor.
Dominic Cummings claimed the PM had once had “possibly illegal” plans to get Tory donors to fund the work.
The government said “costs of wider refurbishment in this year have been met by the prime minister personally.”
But Labour said he needed to fully disclose who paid for the work in the first place.
Party leader Sir Keir Starmer said: “Publish the details, have the full inquiry. If there’s nothing to see here… have a full inquiry.”
Once Mr Johnson’s closest ally, Mr Cummings was forced out of his Downing Street role at the end of last year, following an internal power struggle.
In a blistering attack on his old boss, Mr Cummings questioned the prime minister’s “competence and integrity”.
On Friday, in his first blog post since leaving his role, Mr Cummings:
denied leaking text messages sent between Mr Johnson and businessman Sir James Dyson
denied leaking details of the second coronavirus lockdown in England in November
alleged Mr Johnson had considered trying to block an inquiry into the leak in case it involved a friend of his fiancee Carrie Symonds – a claim rejected by No 10
claimed the prime minister once had a “possibly illegal” plan for donors to pay for renovations of his Downing Street flat
Mr Cummings promised to answer questions about “any” issues when he appears before a Parliamentary inquiry into the government’s pandemic response on 26 May.
This is an explosive intervention from a man Boris Johnson used to count on as one of his closest allies.
And if you’re tempted to roll your eyes and think it’s just sour grapes from a jilted adviser, think again.
Dominic Cummings’ blog is proof that he is willing to lift the lid on his time at the heart of Downing Street, regardless of how it reflects on the prime minister.
Beyond his denial of leaking text messages, he has also given his version of events relating to two potential political weak spots for Boris Johnson.
They are the questions over the financing of the renovation of the Downing Street flat and the leaking of a plan to impose a lockdown.
The level of detail shows that Mr Cummings is willing to expose others while defending himself and lay bare the inner workings of No 10.
