Sir Keir Starmer has vowed to “leave no stone unturned” in answering how the state “failed” to protect the three young girls murdered by Axel Rudakubana.
The Prime Minister said Britain “will rightly demand answers” after it was revealed that the Southport killer had previously been referred to the government's counter-terrorism Prevent programme.
Following the 18-year-old’s guilty plea on Monday, Sir Keir said his thoughts were with the families of the victims Alice da Silva Aguiar, nine, Bebe King, six, and Elsie Dot Stancombe, seven.
He added: “The news that the vile and sick Southport killer will be convicted is welcome.
“It is also a moment of trauma for the nation and there are grave questions to answer as to how the state failed in its ultimate duty to protect these young girls.
“Britain will rightly demand answers. And we will leave no stone unturned in that pursuit. “At the centre of this horrific event, there is still a family and community grief that is raw; a pain that not even justice can ever truly heal.”
It comes after Nigel Farage signalled that Home Secretary Yvette Cooper must appear in Parliament and account for why Rudakubana’s terror links were not revealed sooner
The Reform UK leader was among the politicians critical of how the Government responded to the attack, as Patrick Hurley, the Labour MP for Southport, said Rudakubana’s guilty plea would spare the families of the three murder victims a lengthy trial.
On Monday – the first day of his trial – Rudakubana, 18, of Banks, Lancashire, pleaded guilty to the murders of three young girls in Southport last July.
Summer riots which saw violence across the country were sparked by the stabbings carried out by Rudakubana.
He also admitted production of a biological toxin, ricin, on or before July 29, the date of the attack, and possession of information likely to be useful to a person committing or preparing to commit an act of terrorism.
Alice da Silva Aguiar, Bebe King and Elsie Dot Stancombe died following the attack at the Taylor Swift-themed class on a small business park in the seaside town shortly before midday on July 29.
The defendant, who was 17 at the time, admitted their murders as well as the attempted murders of eight other children, who cannot be named for legal reasons, class instructor Leanne Lucas and businessman John Hayes.
Mr Farage said a “vacuum of information” about the suspect had fuelled the riots, and claimed Reform UK had been blocked from asking questions about potential terror links to the attacks in the House of Commons.
“There was nothing about what I asked that would have in any way threatened contempt of court. This is basic background information that the public was entitled to,” he added.
Mr Farage continued: “I think that the Government are responsible for the most astonishing cover-up.
“I think that we need an apology from the Home Secretary and an explanation as to why we have been denied the basic truth.”
The Reform leader’s “cover up” claim relates to Rudakubana’s admission he possessed an al Qaida training manual in PDF form, something not revealed in the immediate aftermath of the attack.
Asked if he would be calling for the Government to address the case in the Commons, Mr Farage replied: “We will, as a party, table an urgent question on this. Absolutely.”
Tory leader Kemi Badenoch insisted there needs to be a "complete account of who in Government knew what and when" in the case.
"As we learn more details of Axel Rudakubana's horrific crimes, my thoughts are first and foremost with the victims' families,” she said.
"We will need a complete account of who in Government knew what and when. The public deserves the truth.
"This case is still in court and there are, properly, limits on what can be said at this stage.
"But once it concludes on Thursday with sentencing, there are many important questions the authorities will need to answer about the handling of this case and the flow of information."
Rudakubana will be sentenced on Thursday.
