LABOUR has warned that corruption allegations against Boris Johnson “cannot be swept under the carpet,” as pressure mounts on the Prime Minister to explain his relationship with US businesswoman Jennifer Arcuri.

The corruption scandal intensified over the weekend as the Sunday Times published emails appearing to show Mr Johnson wrote a letter of recommendation for Ms Arcuri to be head of a technology quango when he was London mayor.

Ms Arcuri, a former model, was a 27-year-old business studies student when Mr Johnson allegedly gave her the reference in 2012.

The role, as CEO of Tech City, came with a salary of £100,000 a year and was intended for “proven business leaders.”

In an email Ms Arcuri later allegedly reflected: “I still have the letter of rec from Boris. Hahaha.

“To think that we asked him to write us a recommendation for the CEO of Tech City is just hysterical.”

She listed “Boris Johnson, Mayor of London” as a reference on the application, according to the paper.

Despite the mayor’s backing, Ms Arcuri is not believed to have been shortlisted for the role.

The report adds to mounting questions about the Prime Minister’s past links with Ms Arcuri.

Last month Mr Johnson was referred to the police complaints body to assess whether he should face a criminal investigation over his association with the businesswoman.

It follows reports by the same paper that Ms Arcuri was given £126,000 in public money and privileged access to three foreign trade missions led by Mr Johnson while he was mayor.

He has until Tuesday to respond to a summons from the London Assembly to provide details of the relationship. He could otherwise be asked to make an appearance before the assembly and to hand over private text messages and emails he sent to her.

Labour’s shadow Cabinet Office minister Jon Trickett said: “The allegation that Boris Johnson recommended Jennifer Arcuri for a top government job without declaring his relationship to her is incredibly serious.
 
“Johnson cannot continue to stonewall and refuse to give a full account of his actions.”

He said: “The integrity of the Prime Minister is called into question when he acts as if he believes he can get away with anything.
 
“The public have a right to know if their Prime Minister has in the past misused public funds and abused his office and position of power. 

“This cannot be swept under the carpet.”
 
Ms Arcuri has described any suggestion that she was Mr Johnson’s lover as “complete bulls**t.”

She told the Mirror: “If I was banging the dude and there was some kind of, like trail or sex tape, but there’s nothing.

“There is a human side of my very complex relationship. This is not a Monica Lewinsky.”

She said: “Men just trip over themselves in front of me. They fall in love with me in about 10 minutes … because I know what to say.”

The Prime Minister has denied that any conflict of interest came into his dealings regarding Ms Arcuri.