A surviving member of the Guildford Four has issued a plea for a coroner to examine how the group was wrongly convicted over the IRA blasts.
Paddy Armstrong has applied to make representations at a pre-inquest review into the 1974 Guildford pub bombings.
He and the family of Carole Richardson, another member of the Four, want Surrey coroner Richard Travers to resume a full inquest into the tragedy.
Mr Armstrong lives in Ireland with his wife and children.
Ms Richardson died in 2012.
The pair were jailed alongside Gerry Conlon and Paul Hill in 1975, and served 15 years before their convictions were quashed in 1989.
The Balcombe Street IRA unit admitted responsibility for the explosions in 1976, although no-one else was ever charged.
It is widely regarded as one of the UK's worst miscarriages of justice.
'Never fully investigated'
Soldiers Ann Hamilton, 19, Caroline Slater, 18, William Forsyth, 18, and John Hunter, 17, and plasterer Paul Craig, 21, were killed in the blast at the Horse & Groom on 5 October 1974.
In a joint statement, Mr Armstrong and Ms Richardson's relatives said the families of the five who died deserved to know what happened and who was responsible.
"We hope that the coroner will resume the inquests and will look into how the wrong people were convicted and why the right people, who in detailed confessions admitted committing the bombings, were never prosecuted," they said.
"These are matters that have never been fully investigated and in our view, they should be.
"We hope that after more than 40 years, the truth of what happened that day and subsequently will finally be explored in public and that justice will be done and will be seen to be done."
'Remained good friends'
Paddy Armstrong, then 25, was living in a squat in London with 17-year-old Carole Richardson when they were arrested in 1974.
After sporadic contact while they were in prison, they went their separate ways after they were released in 1989.
This year, in a rare interview, Mr Armstrong told the BBC: "We were still good friends when we split up."
He said he could not believe it when he heard Ms Richardson had died of cancer.
Their lawyer, Charlotte Haworth Hird, said a huge number of questions remained over the bombings.
She said: "Given the history of the case, including the wrongful convictions that followed, it is important that my clients are provided with the opportunity to participate in any inquest."
The coroner announced the new hearing following an application by KRW Law.
It is representing both Ann McKernan, sister of Guildford Four member Gerry Conlon, and a soldier who survived the blasts. Mr Conlon died in 2014.
KRW Law said the original inquest opened in 1974 but there was no record of it being resumed.