While Downing Street continues to deny any wrongdoing on Mr Johnson's part, the row over the luxurious revamp of his No 11 flat has escalated to a full-blown political crisis. The Beeb's political editor said while Mr Johnson has gotten in trouble over his lack of truthfulness in the past, this time around it is much more serious.
Ms Kuenssberg said: "The Prime Minister's relationship with the truth is under intense scrutiny at the moment. He is refusing to give full explanations on some issues.
"There are questions about how the refurbishment of his Downing Street flat was initially funded, and about incendiary comments he made last autumn as England was about to enter a second lockdown."
She added: "It is not the first time in Boris Johnson's long career that he has faced questions about his conduct and character. But the stakes are so much higher now."
This weekend reports suggested Tory party staff were sent an email ordering them to hand over all communication related to the renovations or they will face criminal consequences.Insurance Loans Mortgage Attorney Credit Lawyer
The BBC's Laura Kuenssberg said the stakes are high for Boris in the row over the flat revamp (Image: BBC)
Boris Johnson is under mounting pressure over the flat revamp (Image: GETTY)
The Electoral Commission and Simon Case, the UK's top civil servant, are conducting separate probes into the financing of the redecoration of the flat above 11 Downing Street.
Mr Johnson shares the flat with his fiancée Carrie Symonds and their one-year-old son Wilfred.
The Times and The Sun reported all Conservative Party staff received an email from human resources in the name of Alan Mabbutt, a senior official and registered legal officer, about the
Commission's inquiry which told them: "You are put on notice that this is a criminal investigation."
The email instructed that all communications had to be provided to the investigation by May 7.
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