The Electoral Commission has opened an investigation into how the refurbishment of Boris Johnson’s Downing Street flat was funded.
The body said in a statement that there are “reasonable grounds” to suspect an offence took place.
The government has said that Boris Johnson paid the £58,000 cost of the flat refurbishment, but it is unclear at which point he paid the money or how it was funded.
Johnson told the House of Commons on 28 April that he paid for the flat renovation personally, in repsonse to questions from Labour leader Sir Keir Starmer.
An Electoral Commission spokesperson said: “We are now satisfied that there are reasonable grounds to suspect that an offence or offences may have occurred. We will therefore continue this work as a formal investigation to establish whether this is the case.
“The investigation will determine whether any transactions relating to the works at 11 Downing Street fall within the regime regulated by the Commission and whether such funding was reported as required.
“We will provide an update once the investigation is complete. We will not be commenting further until that point.”
There have been reports that Johnson was loaned the money for the flat refit by the Conservative Party or by Tory donors.
The Prime Minister’s former chief adviser Dominic Cummings said on 23 April that he thought having donors pay for the refit was “unethical, foolish, possibly illegal”.
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