The American businesswoman whose relationship with Boris Johnson sparked a misconduct scandal said he cast her aside “like a gremlin”.

Jennifer Arcuri had a close personal relationship with the Prime Minister during his time as Mayor of London.

She received £126,000 in publicly funded grants – including from funds overseen by Mr Johnson.

Ms Arcuri also went on three international trade trips with the Mayor, despite not meeting the criteria to be a delegate on multiple occasions.

But Mr Johnson never declared his relationship with Mr Arcuri.

Under City Hall rules, the Mayor, London Assembly members and senior officials must declare potential conflicts of interest with their work.

Now Ms Arcuri says the Prime Minister has treated her “like one of Kennedy’s girlfriends” since the story was first reported.

In an ITV documentary aired last night, the former model said she wished Mr Johnson had declared their relationship so she could have avoided “humiliation”.

Addressing the Prime Minister directly, she said: “You know that I’ve been nothing but loyal, faithful, supportive, and a true confidante of yours.

“I’ve kept your secrets, and I’ve been your friend. I don’t understand why you’ve blocked me and ignored me as if I was some fleeting one-night stand or some girl that you picked up at a bar because I wasn’t – and you know that.

“I’m terribly heartbroken by the way that you have cast me aside like I am some gremlin.”

The American businesswoman said she tried to seek advice from the Prime Minister after the story was reported in the press, but was turned away by an aide.

She said: “I was brushed off as if I was one of Kennedy’s girlfriends showing up to his White House switchboard, you know, here to do my calling”.

She added: “I’m the one on the ground having to pick up the pieces. I am the collateral damage that’s left behind.”

Though Ms Arcuri has been reluctant to confirm the nature of her relationship with Mr Johnson, she used the word ‘affair’ for the first time in the ITV documentary.

Reflecting on her uncertainty about handling media attention, she said: “The people that reached out told me to categorically deny, deny, deny.

“The other half told me to admit the affair, fall on the sword, get it over with.”

Ms Arcuri’s close personal relationship with Mr Johnson was first reported by The Sunday Times in September.

Following that report, the London Assembly launched an investigation into Mr Johnson’s conduct as Mayor of London.

That probe has since been paused, until the Independent Office of Police Conduct (IOPC) rules on whether it will investigate – at which stage Assembly members will decide whether to pursue their inquiry further.

But the IOPC has said it is unlikely it will reach a decision before the General Election.

Last month, an internal Government investigation found that a £100,000 grant Ms Arcuri received earlier this year was appropriate.

Mr Johnson has been unwilling to comment extensively on the allegations against him, but has said his actions were “in complete conformity to the rules”.

Responding to the ITV documentary, a spokesperson for the Conservative Party said: “Any claims of impropriety in office are untrue and unfounded.

“Given that City Hall has made an unfounded complaint to the Independent Office for Police Conduct, we will not be making detailed comments until that process has finished.”