Labour has accused Boris Johnson of lying over who paid for the refurbishment of his Downing Street flat as the party demanded an investigation into a potential “cover-up”.
One shadow minister demanded: “We really need to know who the prime minister is beholden to.”
It comes on another day of negative headlines and accusations about the PM.
The government is on the record as saying Johnson has covered the cost of the renovation, which some reports have suggested totalled £200,000.
However, the key question remains over who initially paid for it, something that would have to be declared.
His former chief adviser Dominic Cummings has said Johnson wanted donors to “secretly pay” for the work.
Watch: Angela Rayner calls for Boris Johnson to 'come clean' over refurb funding
On Monday, ITV reported Johnson received a loan from the Conservative Party, which he is now paying back. However, this has not been declared. Number 10 refused to deny the report on Tuesday.
Meanwhile, Johnson himself did not deny discussing using donations to fund the refurbishment on Monday, when he said “if there’s anything to be said about that, any declaration to be made, that will, of course, be made in due course”.
Shadow health secretary Jonathan Ashworth told BBC Breakfast on Tuesday: "We really need to know who's given the loan, who's given the money, because we need to know who the prime minister is beholden to.
“Who has paid for his furniture, for the sofa, for the bed that he sleeps in? And we haven’t had that full and frank explanation from the PM so far.
“To be honest, he lied yesterday. That's not good enough."
Simon Case, the head of the Civil Service, has been tasked with reviewing the refurbishment of the flat, which is in 11, Downing Street.
Last month, Johnson’s then-press secretary Allegra Stratton denied any party funds were used for refurbishments – contrary to the government’s non-denial on Tuesday.
Labour deputy leader Angela Rayner has now called for Case’s review to investigate Stratton’s comments.
In a letter, she urged him to probe “whether the former press secretary knowingly misled journalists and the public, or was misled herself by senior members of the government who seem intent on a cover-up”.
Stratton, who moved roles earlier this month after Downing Street scrapped plans to hold televised press briefings fronted by her, is yet to respond.
Watch: What is the row between Boris Johnson and Dominic Cummings all about?