The businesswoman tells ITV show that she is heartbroken, humiliated – and that the PM hangs up the phone on her

The US businesswoman Jennifer Arcuri has accused Boris Johnson of brutally casting her aside “like some one-night stand” and leaving her “heartbroken” since he became prime minister and the controversy over their four-year relationship became public.

In an outspoken interview with ITV’s Exposure, to be broadcast on Sunday, the tech entrepreneur also tells the journalist John Ware that Boris Johnson has refused to take her phone calls at Downing Street and has cut her off before she could initiate a conversation.

Addressing her words directly to the prime minister, who actively championed her business interests during his time at City Hall while failing to declare their friendship, Arcuri says: “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. And 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. And I’m terribly heartbroken by the way that you have cast me aside like I am some gremlin ... He should know me well enough to know who I am ... Shame on him for not answering the phone.”

While Arcuri refuses to divulge the nature of their relationship she is clear that they were very close for several years.

She tells Ware in the programme When Boris Met Jennifer that she wishes he had declared their friendship and been above board about it to avoid the resulting humiliation. She says it was clear that the prime minister was “worried” about making the relationship public because of all the questions that would be asked.

Referring to one recent call to Johnson, she says: “He heard my voice. And I knew it was him. And he hung up. He said ‘Yes, hello’ and I simply asked: ‘Why did you block me?’ I wasn’t calling to cause problems, I merely just wanted a simple ... acknowledgement for what had happened.”

On another occasion, shortly after Johnson became prime minister, Arcuri says she was very keen to speak to him because she had heard that reporters were contacting her friends.

“When I expressed the interest to want to speak to him, I was told: ‘There are bigger things at stake’, and 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, you know, calling. And I felt so disgusted and humiliated that I was told: ‘Bigger things are at stake; never mind you, he’s too busy for you’.”

Facebook Twitter Pinterest Jennifer Arcuri in London on Friday. Photograph: Stan Kujawa/Stan Kujawa/Mirrorpix

Arcuri said that, when she tried his personal phone on yet another occasion, she was summarily passed to someone who spoke to her in a language she believed to be Chinese.

But it is her suggestions that Johnson was both aware, and concerned about, the need to declare interests that could prove to be the most damaging to the prime minister. On becoming mayor of London in 2008 Johnson had to sign up to a code of conduct requiring that he not use his position to gain financial or other benefits for himself, his family or even his friends.

After meeting Arcuri in 2012, however, he spoke four times at events to promote her tech business interests, which she talks about in the programme. It is also alleged that Johnson helped secure Arcuri places on prestigious overseas trade trips which she recognises have helped her career and benefited her. The ITV programme claims Arcuri and Johnson had an affair that lasted more than four years. During that time Johnson wrote to the City Hall monitoring officer on nine occasions declaring various personal interests. Arcuri’s name did not appear on any of those letters.

Johnson has denied any impropriety or having broken any rules. However, the Independent Office for Police Conduct (IOPC) has been asked to consider whether Johnson, who as mayor was responsible for London’s policing, should be investigated for misconduct in public office over his failure to declare his relationship to Arcuri.

Among the allegations being investigated by the IOPC are questions over a payment of £126,000 of public money to Arcuri’s businesses and why she was on three overseas trade missions with Johnson, despite not qualifying as a delegate.

Last weekend the Observer revealed that an IOPC announcement on whether there should be a criminal investigation had been postponed until after the general election, prompting claims that the ruling had been suppressed to prevent Johnson being damaged during the campaign.

After publication, an IOPC spokesperson said: “The IOPC strongly refutes claims published in the Observer. This matter has not been finalised. We have not delayed any announcements on the status of the referral. Our assessment of this matter is ongoing as we continue to collect information and receive legal advice.”

Referring to the last few months Arcuri says: “It’s caused nothing but utter chaos, destruction and sheer disappointment on many fronts ... and as a result I am the collateral damage that’s left behind. I mean the prime minister hasn’t been affected. He puts his head in the sand and looks the other way. I’m the one on the ground having to pick up the pieces from my name and my integrity and my character and my business, you know, – all these things that I, you know, never intended to have to explain publicly.”

• This article was amended on 20 November 2019 to add the IOPC spokesperson’s comment.