Cheryl James and Sean Benton both died at Deepcut in 1995

The formal invitation to meet Adam Ingram was issued on Wednesday.

The families will be able to voice their concerns over the deaths - but only when a police investigation has been completed.

The four deaths at the barracks in Surrey, between 1995 and 2002, were attributed by the Army to suicide - which the relatives have vehemently disputed.

The families have campaigned for a public inquiry into the deaths and in June received the support of a cross-party group of 173 MPs who signed an early day motion.

The dead soldiers Sean Benton, 20, from Hastings, East Sussex, 1995 Cheryl James, 18, from Llangollen, north Wales, 1995 Geoff Gray, 17, from Seaham, County Durham, 2001 James Collinson, 17, from Perth, Scotland, 2002

Independent forensic expert Frank Swann was hired by the families of the soldiers to investigate the deaths and spent six weeks inside Deepcut earlier this year gathering evidence.

The formal invitation, sent in a letter to the relatives, came on the same day a Ministry of Defence (MoD) report on young recruits was released.

It said some at Deepcut had been "victimised".

The MoD study was based on visits to 14 training bases over the past two months to assess the impact of new measures announced in February to improve the lives of new recruits.

It found the system was proving "remarkably successful" in turning out high-quality troops but found problems at the Army's Phase 2 establishments - like Deepcut.

Questionnaires completed anonymously by 96 recruits at Deepcut found about a quarter said they had been victimised, and more than half felt lonely.

Geoff Gray died at Deepcut in 2001, James Collinson the following year

The number who said they had experienced bullying was less than 10%.

The father of Private Geoff Gray, one of the soldiers to die at Deepcut, said the invitation to meet the minister should have been made six months ago.

Mr Gray, also called Geoff, said: "My number one aim is to know what happened to my son.

"On a broader scale we need a public inquiry into non-combat deaths as a whole.

"If the government washes its dirty laundry in public and it's done nothing wrong, fair enough, if not there needs to be a change."

An MoD spokesman said: "It's always been the intention to meet the families once the police investigation is complete.

"We've known for some time it's nearing completion but that's out of our hands."