Boris Johnson has again declined to talk about a late-night row involving his partner, saying it is "simply unfair" to "drag" his loved ones into politics.
The former foreign secretary, who is the frontrunner to become Britain's next prime minister, was involved in an incident at the flat he shares with his girlfriend Carrie Symonds.
Concerned neighbours allegedly called the police after his partner was heard screaming and shouting "get off me".
Officers attended and found no offence had occurred and everyone was safe.
When asked about what happened in the early hours of Friday, Mr Johnson told the BBC: "I...would love to tell you about all sorts of things Laura [Kuenssberg, the corporation's political editor] but I've made it a rule over many, many years and I think you've interviewed me loads of times, I do not talk about stuff involving my family, my loved ones.
"And there's a very good reason for that.
"That is that, if you do, you drag them into things that, really is, is, in a way that is not fair on them."
Mr Johnson was asked whether privacy meant more to him than public trust and said in response: "Yes I get that, I totally get that.
"But my key point though is that the minute you start talking about your family or your loved ones, you involve them in a debate that is it is simply unfair on them."
Mr Johnson was also asked about photos of the couple holding hands, apparently taken in Sussex over the weekend, which emerged in the media on Monday.
There has been some speculation that the images were staged by Mr Johnson's campaign.
When it was put to him that he was "trying to have this both ways", he dodged the question, saying "I just do not go into this stuff" and referring back to "innumerable statements I gave when I was mayor".
Mr Johnson continued: "Actually I think what people want to know is what is going on with this guy, does he, when it comes to trust, when it comes to character all those things, does he deliver what he says he's going to deliver?
"And that is the key thing."
On Brexit, Mr Johnson told the BBC that Theresa May's deal was "dead" and expressed confidence that he could strike a new agreement with Brussels before the new deadline of 31 October.
"I think actually that politics has changed so much since 29 March [the original Brexit day]," he said.
"I think on both sides of the Channel there's a really different understanding of what is needed."
He called for "creative ambiguity" over the £39bn Brexit divorce bill that Britain has signed up to pay - and said preparations should be made for a no-deal exit.
"I think the £39bn is at the upper end of the EU's expectations but there is it, it's a considerable sum," Mr Johnson said.
"I think there should be creative ambiguity about when and how that gets paid over."
He called on the UK to "abandon the defeatism and negativity" and claimed the way out of the Brexit deadlock was "to prepare confidently and seriously for a WTO [World Trade Organisation] or no-deal outcome".
He added: "It is not where I believe for a moment we will end up.
"But in order to get the result that we want, in order to get the deal we need, the commonsensical protraction of the existing arrangements until such time as we have completed the free trade deal between us and the EU that will be so beneficial to both sides.
"The commonsensical thing to do is to prepare for a WTO exit."
However, a majority of MPs have expressed their opposition to a no-deal Brexit, something which they argue would hit the economy and disrupt everyday life.
Despite this strength of feeling, Mr Johnson claimed he would be able get such a no-deal Brexit through parliament.
"I think that MPs on both sides of the House also understand that they will face mortal retribution from the electorate unless we get on and do it," he said.
"People want to get this thing done.
"They want to get it done sensibly... and they want to get it done in a way that allows us to move on which is why I think people are yearning, they're yearning for this great Incubus to be pitchforked off the back of British politics."
Mr Johnson said there were "abundant, abundant technical fixes" that could solve the Irish border issue, a key sticking point in the Brexit negotiations.
But when pressed on what would enable to UK to avoid any backstop - an insurance policy the EU has insisted on to avoid a return to a hard border - Mr Johnson could not name an existing technology.
A key plank of Mr Johnson's Brexit plan is his belief that he can "disaggregate" parts of Mrs May's deal and sort them out in what has become known as an implementation period.
This period - otherwise known as a transition period - would see the UK preserve the status quo of EU membership while a future relationship is put in place.
But critics of this approach have pointed out that if there is no deal in place with the EU, there is no implementation period.
Mr Johnson said he would seek an "agreement" with the EU that issues such as the Irish border would be "tackled on the other side of 31 October", declaring: "It's not just up to us."