Keir Starmer has warned the two Conservative leadership candidates, Robert Jenrick and Kemi Badenoch, against undermining police efforts in the investigation into the Southport attack. Speaking at prime minister’s questions, Starmer said it was important to allow police and prosecutors to “do their difficult job” and that all MPs had a choice to make to “either support the police in their difficult task or they could undermine the police in their difficult task”. Police on Tuesday announced that Axel Rudakubana, 18, the suspect accused of murdering three girls in Southport, was facing new charges of possessing terrorist material and producing the highly toxic poison ricin. Badenoch had said it was “quite clear that there are serious questions to be asked of the police, the CPS [Crown Prosecution Service] and also of Keir Starmer’s response to the whole situation”. While Jenrick said the attack was of “immense public concern” and that people “had a right to know the truth straight away”, but that he was “seriously concerned that facts may have been withheld”. At the start of the session, the speaker of the Commons, Lindsay Hoyle, issued a stern warning to all MPs against making remarks in the Commons that could prejudice the trial. Despite this, Richard Tice, the Reform UK MP for Boston and Skegness, asked Starmer if he agreed with the independent reviewer of terrorism legislation, Jonathan Hall, that the government should be more open about criminal investigations to avoid any information gap being filled by social media. Responding to Tice’s question, Starmer said: “It is very important the police and prosecutors are able to do their difficult job, and all of us in this house have a choice to make, including both candidates to be the next Tory leader, they can either support the police in their difficult task, or they could undermine the police in their difficult task. I know which side I’m on.” Hall had earlier told BBC Radio 4’s Today programme: “The government has to be aware, and will be aware, that if there is an information gap, particularly in the mainstream media, then there are other voices, particularly in social media, who will try and fill it. “I would always say to the government – and do say to the government, as I say to the police – if there is information that you can give, put it in the public domain, and be really careful that you don’t fall into the trap of saying: ‘We can only say zilch, because there are criminal proceedings.’” As part of his caution, Hoyle acknowledged that all MPs “wish to see justice done” in the case, and would have “legitimate questions about the circumstances of the case”, but stressed that at the heart of the trial were three young girls who had been killed. At the beginning of PMQs, the speaker said: “It is of paramount importance that nothing is said in this house which could potentially prejudice a proper trial or lead to it being abandoned. I know it can be frustrating when we can see reports in the media of the matters that we are not free to discuss here, but that arises from parliament’s constitutional relationship with the courts. More importantly, at the heart of this case are three young girls.”