A US businesswoman at the centre of a misconduct controversy involving Boris Johnson says he should "man up" and call her.
Jennifer Arcuri claims she texted the prime minister last week, accusing him of "ignoring and blocking" her.
She allegedly received favourable treatment during Mr Johnson's time as mayor of London due to their friendship - claims he denies.
The prime minster has previously said he acted "with full propriety".
Speaking to the BBC's Victoria Derbyshire programme on Monday, Ms Arcuri said she called Mr Johnson last week, before he hung up and refused further calls from her.
She said: "I am very upset that he could not man up and pick up the phone and call me."
Reading from her mobile phone, she claims to have texted Mr Johnson after the phone call, asking: "Is this the price of loyalty, to be hung up on, ignored and blocked?
"Why would I remain silent if you can't even speak to me, and I've been nothing but loyal to you?"
Asked whether Mr Johnson called her when he was busy as London mayor, Ms Arcuri replied "absolutely".
She said: "This was why it was so hard for me to date, because every guy would tell you they'd call and never follow up.
"Not Boris Johnson. Every time he told me he would call, he called me. I was convinced this was a man of his word, because I couldn't believe the fervent, linear focus which he had on me.
"And I assure you, it was not just a sexual intention.
"He actually was very intrigued by my energy, my ability to get things done. He loved my events and he saw the way I could work a room, the way I met everybody."
She refused to say whether she dated the prime minister but accused him of "feeding her to the wolves" in his handling of the allegations surrounding the pair.
Ms Arcuri added: "He didn't have to ignore me. It could have been a 30-second phone call, just to let me know that he's acknowledging the fact that he, while he gets to be prime minister, gets to feed me to the wolves - and I find that really disturbing."
In an earlier interview with ITV's Good Morning Britain, she refused to say whether she had an affair with Mr Johnson.
The entrepreneur revealed she also called the prime minister back in August.
Ms Arcuri says he answered the phone before it was passed to someone speaking English in a Chinese accent, in an apparent attempt to "mock" her.
She denied that he should have declared their friendship as an "interest" when he was London mayor.
Ms Arcuri said there was "no interest" to declare, adding: "He didn't do me any favours."
When pressed again on this, she said: "If declaring me as an interest would have saved me this entire embarrassment and humiliation... then yes, I wish he had."
She added it would have been the "transparent and open" thing to do.
When asked if he should have declared their friendship, Mr Johnson previously told the BBC's Andrew Marr Show that everything was done "with full propriety" and said there was "no interest to declare".
Her BBC interview comes after she accused Boris Johnson of casting her aside as if she was a "gremlin".
In an interview broadcast by ITV on Sunday, she said she had kept his "secrets" and could not understand why he had "blocked and ignored" her requests for help to handle the media interest surrounding the allegations.
Addressing the prime minister, she said: "I'm terribly heartbroken by the way that you have cast me aside like I am some gremlin."
In response to the programme, the Conservative Party said that any claims of impropriety in office by Mr Johnson were "untrue and unfounded".
The statement added: "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 is finished."
Mr Johnson's friendship with the entrepreneur first came under scrutiny when the Sunday Times reported in September that Ms Arcuri's business received £126,000 in public money along with privileged access to three foreign trade trips led by Mr Johnson when he was mayor, between 2008 and 2016.
The Greater London Authority (GLA) - whose job it is to oversee the conduct of the mayor - launched a probe into the alleged conflict of interest following the paper's report.
That investigation was paused after the authority referred the claims to the police watchdog, the Independent Office for Police Conduct (IOPC).
The watchdog will now decide whether or not to investigate the prime minister for a potential criminal offence of misconduct in public office - before the GLA decides whether to continue its own probe.
Last month, a government review ruled that a £100,000 government grant given to Ms Arcuri's business was "appropriate".