It was a Mail on Sunday headline with all the ferocity usually reserved for general elections, directed squarely at a political opponent. But in this case, the traditionally Conservative-supporting title was not targeting Labour.

The party in its crosshairs was Rupert Lowe’s Restore Britain, the vehemently rightwing outfit that regards Nigel Farage’s Reform UK as too weak on deporting migrants.

“Restore Activists at ‘White Supremacy Summit’,” declared the front page. It claimed supporters canvassing for Lowe’s party before this week’s Makerfield byelection had attended an event that hosted calls for “a white-only Europe”.

Unusually, the Mail on Sunday’s vehemently anti-Restore editorial was displayed prominently on its app through much of the weekend. “Anyone who really cares about Britain won’t vote Restore,” it stated, asking voters to back Reform.

Restore Britain described the story about the summit as “totally irrelevant” and a “hit piece”.

The next day, however, the Daily Mail followed up with another blow. “Restore is the ‘new home for neo-Nazis’”, it said, citing Lowe’s claim over the weekend that if the far-right activist Stephen Yaxley-Lennon, known as Tommy Robinson, wanted to join Restore, it was “up to him”.

A Reform source supplied the killer quote used for the headline.

Lowe himself saw the attacks as a sign of success. “Two Daily Mail front pages in a row abusing Restore Britain in the most spectacular fashion,” he said. “We’ve got the buggers on the run.”

However, the prominence and strength of the stories have also caught the eye of senior figures in Westminster and the media, who view it as a sign of how the rightwing press is reacting to the fracturing of the British right.

Reform figures believe that the emergence of Restore, and its even more stark approach to deporting “millions and millions” of people from the UK, could help push the Mail and other titles towards it as the acceptable option for its readers.

The immediate driver of the Mail’s endorsement was this week’s pivotal Makerfield byelection, in which Andy Burnham is attempting to return to parliament and challenge Keir Starmer for the Labour leadership.

While Burnham is the favourite, Reform is his challenger and there is a realistic possibility that Restore’s splitting of the rightwing vote could be the difference.

The approach to Restore by the right-leaning media has not been consistent, however. Over the same weekend as the Mail on Sunday’s attack, the Telegraph ran a full-page feature interview with Lowe, in which he railed against “woke creeps” who criticise his party.

While there has been a widespread perception that the Telegraph’s politics have drifted further to the right since the Brexit vote, its imminent new owner – the German media company Axel Springer – will be significant in defining its political direction.

In fact, the politics of the Politico owner have also caused intrigue, after its titles ran opinion pieces first by Elon Musk and, more recently, by Viktor Orbán weeks before Hungary’s elections.

It remains unclear how the company, overseen by Mathias Döpfner, wants to position the Telegraph within Britain’s rapidly fracturing politics.

While political endorsements are not on the minds of editors this far out from a general election, senior figures among Britain’s right-leaning titles readily point out how messy the political scene has become. “The whole landscape – from hard left to hard right – looks chaotic,” said one.

Current coverage remains a far cry from the once united pro-Conservative approach, however.

“What you’ve got is decades of essentially right-of-centre UK press and proprietors backing the Conservative party, but now that rightwing consensus is being fractured,” said Steven Barnett, professor of communications at the University of Westminster.

“The Conservative party must be thinking to itself now: where is our support going to come from? If the Mail is going to be at least flirting with Farage – and I think they have been doing some flirting – that on its own means come the next election, they’re not going to be as full-throated in their support for the Conservative party.

“I think they’re still feeling their own way in a new political environment, where the papers themselves are not quite sure where their readership stands.”

Lowe himself suspects that the established rightwing media outlets are now rallying behind Farage. As a result, he has been accusing Farage of a charge the Reform leader is not used to facing: that of being part of the political establishment.

“If you look at the mainstream media, it is now pushing Nigel,” he told the Spectator magazine earlier this year.