Jack Merritt, 25, and Saskia Jones, 23, were killed on Friday when Usman Khan, a man convicted of terrorism offences in 2012, went on the rampage with kitchen knives at a prisoner rehabilitation conference beside London Bridge.

Confronted by bystanders, including a Polish man brandishing a narwhal tusk and others with fire extinguishers, Khan, who was wearing a fake suicide vest, was wrestled to the ground. He was then shot dead by British police.

A vigil in Guildhall Yard, in the heart of the City of London, will be held to honor the dead, those injured, the emergency services and the members of the public who tackled Khan.

With less than two weeks to go until the Dec. 12 snap election, British politicians sought to apportion blame for the early release of Khan - who was released despite a warning from the sentencing judge in 2012 that he was a danger to the public.

“I absolutely deplore the fact that this man was out on the street, I think it was absolutely repulsive and we are going to take action,” Prime Minister Boris Johnson said on Sunday.

Johnson’s Conservatives have championed tough police and prison measures, but opponents have criticized them for overseeing almost a decade of cuts to public services.

More about: London-Bridge-attack   ISIS