A vigil will be held on Monday (local time) to pay tribute to the victims of the London Bridge terror attacks and honour those who responded to the incident.
Former University of Cambridge students Saskia Jones, 23, and Jack Merritt, 25, were fatally stabbed by convicted terrorist Usman Khan, 28, as they attended a prisoner rehabilitation conference on Friday.
The remembrance service will be held at Guildhall Yard in London.
Khan was on licence and wearing an electronic monitoring tag at the time of the attack, which injured three others.
Merritt's family asked for his death not to be used to justify "even more draconian sentences" on offenders, PA reports.
"Jack lived his principles; he believed in redemption and rehabilitation, not revenge, and he always took the side of the underdog," the family said in a heartfelt statement.
"We know Jack would not want this terrible, isolated incident to be used as a pretext by the government for introducing even more draconian sentences on prisoners, or for detaining people in prison for longer than necessary."
In a tweet on Sunday, Merritt's father David wrote: "Don't use my son's death, and his and his colleague's photos - to promote your vile propaganda. Jack stood against everything you stand for - hatred, division, ignorance."
Jones' family said the 23-year-old had a "great passion for providing invaluable support to victims of criminal injustice".
The attack has prompted the Ministry of Justice to review the licence conditions of convicted terrorists released from prison, which Prime Minister Boris Johnson said was "probably about 74" people.