John Dockerty, whose eldest son Major Christopher Dockerty was among the 29 people killed when RAF Chinook ZD576 crashed on the Mull of Kintyre on 2 June 1994, was the oldest member of the long-running campaign for the truth about the disaster.

The Chinook Justice Campaign believes Mr Dockerty, who has died at the age of 96, was the last surviving parent of anyone who died in the tragedy.

His daughter, Nicola Rawcliffe, said: “My father spent the last 32 years wondering why his eldest son and my brother Chris died. He died still fighting for answers. 

“He campaigned with dignity and determination, but it is heartbreaking that he has died without the government and MoD acknowledging the truth about the circumstances surrounding the crash.

“He told me he was disgusted that it has been allowed to fester for as long as it has without the government getting to the bottom of things. Shame on the MoD for letting yet another relative die without answers.

“We are devastated by the loss of my father and horrified that he never saw justice for Chris. It is bad enough that a parent has to bury their child, but a parent having to ask the state as to why they died adds insult to injury.”

A number of the Chinook families will travel to Westminster on Wednesday to meet the UK government’s victims minister, Alex Davies-Jones. They will be joined by Sorcha Eastwood MP, who leads the cross-party group of MPs supporting the families.

Mark Stephens CBE from Howard Kennedy LLP, solicitor for the families, said: “These families are not simply bereaved. They are victims who have spent more than three decades trying to establish the truth about how their loved ones died.

“The continued refusal to fully address the serious questions surrounding the crash has left many of them suffering what psychologists describe as ambiguous loss.

“That is the trauma that occurs when families are denied clear answers about what happened. It prevents proper closure and prolongs grief across generations. John’s death highlights the real human tragedy that these families are facing at the hands of the state- being denied the truth about the circumstances surrounding their loved ones deaths.

“That is why this meeting with the victims minister is so important. The Government must recognise that these families are themselves victims of the state and deserve truth, transparency and accountability.”