Keir Starmer twice declined to criticise Nigel Farage’s response to the Southport atrocity after the Reform party leader was accused of helping spread a conspiracy theory about the knife attack. Farage had questioned “whether the truth is being withheld from us” after the attack that killed three children and injured more on Monday, speculating without information that the suspect may have been monitored by the security services. The Home Office minister Jess Phillips, the former counter-terror police chief Neil Basu and Brendan Cox, the widow of the murdered MP Jo Cox, were among those who criticised Farage for fanning the flames of extremism, as riots took hold in Southport led by the far right. Starmer said he did not want to comment on the words of others, adding: “What I am saying is my focus is on the families, the victims who are at the heart of this, and I think that that should be the focus for everybody. And anybody who says or does anything that impedes their ability to get the justice that they deserve cannot claim to be acting in their best interests, because they’re not.” Farage had posted a video on X on Tuesday in which he said he had “one or two questions” as he speculated about whether the stabbing suspect was being monitored by security services. After the attack, a false name of the suspect and claims he was an Islamist extremist were being circulated on social media, prompting police to say the details were not true. “I just wonder whether the truth is being withheld from us. I don’t know the answer to that, but I think it is a fair and legitimate question,” he said. The Clacton MP has defended his comments, saying it is “quite legitimate to ask questions”. John McDonnell, the former shadow chancellor, said he thought the House of Commons standards commissioner should investigate whether Farage’s video brought parliament into disrepute. “We are at a dangerous moment in our society in which racist thugs feel they have been given permission by the statements of some national politicians to be able to express their racist views and run riot with impunity,” he said. Steve Rotheram, the Labour mayor of Liverpool City region, said Farage’s words were “contemptuous”. “I think the words that senior politicians use are very important and it can be a dangerous weapon for the right, the far right to use as ammunition, against the likes of what has happened here,” he said. “I would say that periods of some of the home secretaries that we had, and certainly some of the prime ministers, trying to divide the country, obviously hasn’t worked out otherwise they’d still be in power, and they’re out with a resounding defeat. “And I’d say most people in this country, most sensible, level minded individuals know the reality of what’s happened in this country. And of course, communities like this, they are very, very welcoming of people who come here to set up new lives. And I don’t think it’s helpful at all when the likes of some of that rhetoric is used.” The former Conservative chancellor, George Osborne said on Thursday that the mainstream political establishment had “been a little bit lame in taking the fight to Farage”. “Farage is a mortal threat to the Tory party, as we’ve just seen at the last general election,” Osborne said on the Political Currency podcast. “He may well be a massive threat to Labour at the next general election. And yet all of the political establishment is saying: ‘Oh, please pipe down a bit and behave yourself, and you’re supposed to be an MP now’ rather than saying: ‘This is an absolute outrage, Farage.’ He’s not going to be deterred by all this. He’s going to thrive on it.” On Wednesday, Basu accused Farage of “giving the EDL [English Defence League] succour, undermining the police, creating conspiracy theories and giving a false basis for the attacks on the police”.