Boris Johnson struggled to explain the Conservative Party's "made up" crime and HS2 figures during a flailing interview.
The Prime Minister was grilled over Home Secretary Priti Patel's claims that a Labour win in this week's general election would spark a violent crimewave.
She said there would be 4,000 more violent assaults, 150 extra sex assaults and 52 more murders each year under Labour - because of the party's opposition to police stop-and-search powers.
LBC radio presenter Nick Ferrari asked Mr Johnson to explain the source of the figures.
He said during the live interview: "How does she come by these figures?
"You're a journalist, I'm a journalist, where'd she get those figures?"
In a rambling reply, the Tory leader said: "The answer, very simply, is that to tackle crime you need not just (to support) the police by putting the police out on the street, which is what we're doing."
When pinned down on the figures once again, Mr Johnson said: "Forgive me Nick, I haven't been able to..." before Mr Ferrari shot back: "She's made them up, Prime Minister, hasn't she?"
Ms Patel's original Daily Telegraph article claimed the figures were from the Conservative research department.
During the LBC interview, Mr Ferrari also suggested the Prime Minister had "made up" figures about the total cost of HS2.
Mr Johnson says HS2 will probably cost "north of £100 billion" even though the current estimate is £88 billion.
Questioned on why he was using the £100 billion figure, he said: "It's a figure I've used many times in the past."
