Boris Johnson should explain why police were called to the home he shares with partner Carrie Symonds, a Cabinet minister has suggested.
International Trade Secretary Liam Fox signalled it was better to be clear about what had happened.
Dr Fox, who backs Mr Johnson’s run-off rival Jeremy Hunt in the battle for the Tory crown, told BBC1’s The Andrew Marr Show: “I think it is always easier to just give an explanation.”
He added: “It is inevitable there is a focus on private lives. That does not concern me. What I am concerned about are the issues.”
Shadow communities secretary Andrew Gwynne said Mr Johnson was “completely unsuitable” to be prime minister after police were called to his partner’s home after reports of shouting and banging.
He told Sky News’s Sophy Ridge On Sunday: “In one sense, of course, it is a private matter, but when you’re running for public office, when you are wanting to be the prime minister of the UK, then these matters are in the public interest.
“I’ve long held the view that Boris Johnson is unsuitable to be prime minister of this country. I’ve had my run-ins with Boris – I, infamously, was almost tackled to the ground in the 2017 general election by this man.”
Mr Johnson repeatedly refused to explain to Tory grassroots at a Saturday hustings what went on at the south London flat in the early hours of Friday morning, saying the party faithful did not want “to hear about that kind of thing”.
Mr Johnson’s campaign for Number 10 was rocked by the revelations that officers were called to the home he shares with partner Ms Symonds by a neighbour who claimed to have been “frightened and concerned” after hearing shouting, “a loud scream” and banging coming from the property.
A poll carried out after the reports emerged suggested Mr Johnson’s support among Tory voters had dropped by more than half, while among the general electorate it indicated he had slipped into second place behind rival Jeremy Hunt.
The Foreign Secretary ramped up his challenge to Mr Johnson on Saturday, saying in an open letter that their “character” was being tested in the final stage of the leadership race and “scrutiny can be uncomfortable”.
When asked at the hustings about the incident, Mr Johnson said people “are entitled to ask about me and my determination, my character and what I want to do for the country”.
But he would not elaborate on the police visit, preferring to talk about his time as mayor of London instead.
Moderator Iain Dale drew heckles from some in the crowd when he asked Mr Johnson whether a person’s private life had any bearing on someone’s ability to discharge the office of prime minister.
“Don’t boo the great man,” Mr Johnson said, but Mr Dale suggested he was “completely avoiding” the question.
Tory grandee Sir Malcolm Rifkind told BBC Radio 5 Live: “If you are a candidate to be prime minister and the police have been called to your house – fairly or unfairly – the fact is there was a police visit. You don’t just say ‘no comment’.
“That implies you may have something you don’t want to disclose.”
Sir Malcolm, who indicated he would back Mr Hunt in the race, added: “It was a lack of judgment to refuse to even make a short comment. All he could have said, quite reasonably, would have been that in all relationships there are occasionally outbursts of anger and disagreement.”
The former foreign secretary rejected a suggestion that Mr Johnson should be allowed to draw a distinction between his private and public life.
“I’m sorry, you don’t have that sort of private life if you’re asking people to choose you to be their prime minister,” Sir Malcolm said.
“Of course there are certain things that are utterly personal, but it’s rather like Michael Gove being asked if he took cocaine.”
The big element in the Boris story isn’t that there was a heated argument, it’s that the police were called.
The police were called by the same person who recorded Boris and gave the story to the Guardian.
— James Cleverly MP (@JamesCleverly) June 22, 2019
On Saturday night the neighbour who rang the Metropolitan Police went public after suggestions that his recording of the row had been leaked to The Guardian with political intent.
Tom Penn said the allegations were “bizarre and fictitious”, explaining in a statement to the paper that he dialled 999 after hearing shouting coming from his neighbour’s flat.
“It was loud enough and angry enough that I felt frightened and concerned for the welfare of those involved, so I went inside my own home, closed the door, and pressed record on the voice memos app on my phone,” the 29-year-old playwright said.
“After a loud scream and banging, followed by silence, I ran upstairs, and with my wife agreed that we should check on our neighbours.
“I knocked three times at their front door, but there was no response. I went back upstairs into my flat, and we agreed that we should call the police.”
The revelations threw Mr Johnson’s leadership campaign into chaos and a poll by Survation for the Mail On Sunday suggested it had struck a blow to his dominant position in the race.
Two surveys suggested Mr Johnson’s lead over Mr Hunt among Conservative voters had been cut from 27 points to 11, while among all respondents Mr Hunt was ahead on 32% with Mr Johnson on 29%.