Boris Johnson sought to give the impression that everything was rosy with his partner Carrie Symonds following their early morning bust-up when “loved up” pictures emerged of the couple holding hands and smiling in a Sussex garden.

It appeared the photographs, which were published online, were stage-managed, aiming to prove their relationship was back on an even keel following days of damaging headlines which some of the former foreign secretary’s political opponents claimed showed he was a flawed character and unfit to be prime minister.

Nimco Ali, the prominent campaigner against female genital mutilation, who is a friend of 31-yearold Ms Symonds, said: “Boris and Carrie are very loved up. They don’t deserve this from creepy neighbours. People in love row once in a while; so what? They are human. If anything this whole thing has brought them even closer together.”

She revealed that, just a day before the contretemps in London’s Camberwell, Ms Symonds treated Mr Johnson to a romantic dinner in a Mayfair restaurant for his 55th birthday.

One source close to Mr Johnson suggested people should be prepared for a “media blitz” in the coming days, with even the possibility of a whistle-stop visit to Scotland being considered.

Another suggested there could be a series of publicity events today in a bid to show the former foreign secretary is not hiding away after the blanket media coverage of the bust-up with his partner apparently sparked by wine being spilled on a sofa.

On Monday night, in an interview with the BBC, he again refused to elaborate on the row at his home in the early hours of Friday, saying: “I do not talk about stuff involving my family, my loved ones” since it is “not fair”.

Mr Johnson also defended his Brexit plan, insisting that it would be possible to agree a new deal with the EU before the October 31 deadline.

Describing Theresa May’s existing agreement as “dead”, he said: “I think on both sides of the Channel there’s a really different understanding of what is needed.”

But he admitted he would need the bloc’s co-operation to avoid a hard border on the island of Ireland and trade tariffs if no deal is secured. 

The latest developments came as:

*the Hunt camp branded Mr Johnson a “bottler” for again failing to agree to a live TV debate on Sky;

*Gordon Brown today intervenes in the Tory leadership contest to warn the former London Mayor will "whip up English Nationalism against Scotland for electoral reasons" and jeopardise the Union if he took power;

*Jeremy Hunt emphasised his devotion to the Union by attacking Nicola Sturgeon’s “war on business,” denouncing hikes to Scottish business rates and income tax;

*the respected IFS think-tank said Mr Johnson’s plan to raise the higher rate tax threshold would cost about £9 billion and benefit four million better off taxpayers, noting it was “not clear spending such sums on tax cuts is compatible with both ending austerity in public spending and prudent management of the public finances”;

*Tobias Ellwood, the Defence Minister, claimed up to 12 Tory MPs would support a no-confidence motion in the UK Government to prevent a no-deal Brexit. Ken Clarke, the former Chancellor, suggested he could be one of them; and

*the leadership ballot is expected to close on Monday July 22 with votes counted overnight, the result announced the following day and the winner entering No 10 on the Wednesday afternoon, allowing Theresa May to take her final PMQs.

While Mr Johnson will appear alongside Mr Hunt in a number of party hustings this week, including a digital one today, his lack of enthusiasm for appearing before the cameras has enabled his rival to hog the media limelight.

The Foreign Secretary used a newspaper article to launch a personal attack on Mr Johnson, saying his premiership would lead to a general election, resulting in Jeremy Corbyn in Downing St and the demise of Brexit.

He also branded his opponent a “coward” and urged him to “man up” and appear alongside him on television.

Mr Hunt appeared on ITV’s Good Morning Britain, launching a broadside at Mr Johnson, saying: “If you are saying the only debates I will do is after people have voted, it’s not showing respect. People need to know what we are going to do.”

On BBC Radio’s Today programme, the Foreign Secretary continued his attack, saying: “The way to earn that trust with Conservative Party members and with the country is to subject yourself to scrutiny, to answer questions about what you actually want to do.

"It is very disrespectful to say that you are not going to do any head-to-head debates, any tough media interviews, for the next two weeks."

Then when Sky News threatened to cancel a planned head-to-head this evening because Mr Johnson was staunchly refusing to take part, Mr Hunt hit out again, saying it was "incredibly disappointing" and risked "cheating" the country out of a "proper contest".

This morning in London, Mr Brown will enter the fray, saying thus far the Tory leadership contest has not addressed the “biggest existential question of all…the threat to the Union”.

Claiming the existence of the United Kingdom is in greater danger than at any point in its 300-year history, the former PM will tell an audience in Westminster Cathedral Hall: “It is under threat from the SNP’s recent but little-publicised shift from a soft to hard version of independence with the abandonment of the pound and their desire to leave the UK single market and customs union.

“And it is under threat from the growing scorn for the Union from the Conservative Party membership and from the favourite to be Prime Minister, Boris Johnson.”

Mr Brown will point to a recent poll in which 63 per cent of Tory members said they would sacrifice the Union as a price worth paying for Brexit.

“Even more worryingly, Boris Johnson is on record challenging the very foundations of the modern Union, demanding a cut in Scottish representation in the UK Parliament, a reduction in the powers of the Scottish Parliament and an end to the Barnett Formula, which allocates resources on the basis of need and changing demography.

“We know the SNP think he is their biggest recruiting sergeant for the independence cause and few think the Union safe in his hands.

“I have no doubt that unless he specifically rules it out, the next Conservative Prime Minister will…play the ‘English card’; whipping up English Nationalism against Scotland for electoral reasons and at a risk to the break-up of the Union,” the former Labour leader will declare.

Declaring he will “fight, fight and fight again for Scotland’s role in Britain,” Mr Brown will add: “It is now urgent those who support Scotland's role in the UK put the case against the two divisive extremes, Nationalist and Conservative, that threaten to blow the United Kingdom apart.”

Meanwhile, in another intervention into the Tory leadership race, David Lidington, Theresa May’s de facto deputy, suggested that Mr Johnson was not as qualified to deal with national security crises as ably as Mr Hunt.

In a speech to the Scottish Law Society in Edinburgh, he asked which candidate could best “shoulder the security responsibilities” under severe pressure as PM and answered: "My judgement is that Jeremy is the one who is best equipped to deal with the '3am call.'"

Asked whether Mr Johnson was a "coward" for avoiding TV debates during the leadership campaign, Mr Lidington replied: "It's wrong and it's also unwise for him to duck out of interviews and debates.

"We're choosing not just a party leader, we're choosing a prime minister, so the country is entitled to know what both the candidates for that office would have as their priorities and how they would go about discharging those responsibilities, so I hope he thinks again and I hope he agrees to take part," he added.

But Conservative supporters of Mr Johnson rallied round their preferred candidate.

Jacob Rees-Mogg, who leads the anti-EU ERG faction, hit out at "Corbynista curtain-twitchers" over the row over Mr Johnson's personal life.

While Conservative colleague Nadine Dorries tweeted: "I've spoken to @BorisJohnson + @carriesymonds I am totally stunned at level of harassment they have had to endure. Hate mail, left wing protests outside their flat, eavesdroppers. Stress is immense, more than most could endure. They are together, strong and united."