The daughter of a murdered police officer has said she is "sickened" to learn that her father's killer is to be released without any prior warning.
Harry Roberts, now 78, opened fire on three unarmed police officers in 1966. He has served 45 years of a life sentence.
Mandy Fox, the youngest daughter of Pc Geoffrey Fox, told ITV News:
With reference to the release of Harry Roberts by the parole board, I would like to complain strongly to the ministry of justice for not informing our family that this release had been granted and was imminent. It has impacted severely on myself as I have health problems compounded greatly by the devastation caused by Mr Roberts and company and it sickens me to know that this is happening without any prior notice being given in order to prepare myself mentally for what is a very emotional time.
What signal does this show our courageous serving police officers throughout the country, who put their lives on the line daily for our protection and safety, it is an utter disgrace and should never have been aloud [sic].
We have not further comments and wish not to be disturbed at this time.
A man who was at the scene of the murder of three unarmed policemen has told ITV News it is a "disgrace" that one of the men responsible for their murders is being released from prison.
Glen Hazell, who was 11, was playing with friends in Shepherd's Bush when Harry Roberts and two associates opened fire on the officers in 1966.
The Parole Board today announced that Roberts, who was handed a life sentence, will be released after serving 48 years, a decision that has sparked fury among police groups.
"I don't think he should be allowed anywhere near the public...it's a disgrace," he told ITV News Senior Correspondent Emma Murphy.
People will be "absolutely sickened" by the release of convicted police killer Harry Roberts, Boris Johnson said.
The Mayor London said "life should mean life" as he criticised the decision to free Roberts, who has handed a life sentence for murdering three police officers in 1966.
"It is perfectly possible that the Parole Board has seen new evidence, I don't know. What I do know is that Londoners will be absolutely sickened by this news," Mr Johnson said.
"They will find it hard to understand how a man who shot dead three police officers in this city in the most horrific fashion can now enjoy the freedom he denied his victims.
"To my mind, in the case of the murder of a police officer, life should mean life."
Home Secretary Theresa May has declined to comment directly on the decision to release convicted police killer Harry Roberts, saying it was a "decision by the independent Parole Board".
The Parole Board has confirmed that a panel has directed the release of Harry Roberts, but declined to reveal when the convicted police killer would leave prison.
Police groups have reacted furiously to the decision.
We can confirm that a three-member panel of the board has directed the release of Harry Roberts.
The decision to release is a matter for the board, which is independent - arrangements and the date of the release are a matter for the Secretary of State for Justice.
We are unable to comment further on the details of this case.
The chair of the Metropolitan Police Federation said the imminent release of convicted killer Harry Roberts is a "total betrayal of policing by the criminal justice system".
Roberts, who was jailed for life for the murder of three unarmed policemen in 1966, could leave prison within days following the Parole Board's decision.
Reacting to news of Roberts' impending release, John Tully tweeted: "A total betrayal of policing by the criminal justice system.
"This man should never see the light of day again, life should mean life."
The decision to release Harry Roberts is a "slap in the face" for the families of his victims, the head of the police federation said.
In a statement to ITV News, Steve White, Chair of the Police Federation of England and Wales, said he was "appalled" by the Parole Board's ruling, adding that officers felt "badly let down".
I am appalled to learn that police killer, Harry Roberts, is being released from prison.
Let’s not forget, this menace murdered three unarmed police officers in cold blood and it is abhorrent news.
This decision by the parole board is a slap in the face for the families of the three police officers he brutally murdered who, once again, are forced to re-live their pain and loss.
It will spark fury among everyone in the police family who will feel badly let down.
This is a betrayal of the police officers who died.
Harry Roberts opened fire on three unarmed police officers after they pulled over his van ahead of an armed robbery near Wormwood Scrubs Prison in 1966.
The murders of PC Geoffrey Roger Fox, 41, Detective Constable David Stanley Bertram Wombwell, 30, and Detective Sargent Christopher Tippet Head, 25 shocked the nation.
Roberts went on the the run for more than 90 days and was eventually found in Hertfordshire following a huge manhunt.
The judge who jailed Roberts described it was "the most heinous crime for a generation or more", and warned that he could spend the rest of his life behind bars.
But Roberts, now 78, could be released within days after approval by the Parole Board.
Police killer Harry Roberts is to be released from prison after more than 45 years behind bars.
Roberts, now 78, was handed a life sentence for the murder of three policemen in Shepherd's Bush, west London, in 1966.
Detective Sergeant Christopher Head, 30, Detective Constable David Wombwell, 25, and Pc Geoffrey Fox, 41, were shot dead without warning while questioning Roberts and two other suspects in a van on August 12, 1966.
His 30-year minimum tariff expired 18 years ago.
He could leave Littlehey Prison in Cambridgeshire imminently after the Parole Board approved his release.
A Ministry of Justice spokesman said: "We do not comment on individuals."
Police staff in England and Wales, including community support officers and fingerprint experts, are to be balloted for industrial action, unions announced today.
The industrial action would be part of a dispute over a 1% pay offer.