Boris Johnson paid for the £200,000 refurbishment of his Downing Street flat himself, according to a senior minister.

Liz Truss, the International Trade Secretary, could not say where he got the money but said she had been assured rules had been fully complied with.

She added that the details would be publicly declared.

The controversy comes after his former advisor, Dominic Cummings, claimed the PM once had "possibly illegal" plans to get Conservative Party donors to fund the works.

It comes amid fallout after the reveal of text messages between Mr Johnson and Sir James Dyson, where the Prime Minister said he would "fix" tax issues for Dyson's staff coming to work in the UK during the pandemic.

Ms Truss – who is the first minister to speak publicly since Mr Cummings issued his incendiary claims on Friday – dismissed the allegations as “tittle tattle”.

“I have been assured that the rules have been fully complied with and I know that he has met the costs of the flat refurbishment,” she told Sky News’ Sophy Ridge on Sunday programme.

“I absolutely believe and trust that the Prime Minister has done that.

“What people want to know is that in line with the rules the Prime Minister has met the cost of this refurbishment. That has happened. All the costs will be declared in line with the rules.

“That, as far as I am concerned, completely answers that question.”

However, Labour has called for the Electoral Commission to mount a full investigation after the explosive claims.

Deputy leader Angela Rayner said there was a “real stench” around the Government and called on Mr Johnson to go to Parliament on Monday to explain what happened.

The cost of the refurbishment to the flat at 11 Downing Street, overseen by Mr Johnson's fiancee Carrie Symonds, reportedly cost £200,000.