Families of two of the 14 servicemen killed when an RAF Nimrod plane exploded in mid-air in Afghanistan have launched legal proceedings against the Government.
A writ served on Defence Secretary Des Browne accuses the Ministry of Defence (MoD) of negligence, failing to minimise risk and breaching the troops' right to life in relation to the accident.
This is the first time the department has faced a legal challenge under the European Convention on Human Rights.
If successful it could open the way for other families to sue the Government over the death of loved ones in Iraq or Afghanistan.
The servicemen were killed when the Nimrod spy plane exploded just minutes after undergoing air-to-air refuelling on September 2 2006.
The cause of the blast was fuel leaking into a dry bay and igniting on contact with a hot air pipe.
The action against the MoD is being brought by relatives of victims Sergeant Ben Knight, 25, and Flight Lieutenant Steven Swarbrick, 28.
Barrister John Cooper, who is acting for the two families, confirmed the legal papers were formally lodged.
He said the relatives of the servicemen wanted the matter to be heard in open court - although this would be unlikely to happen for a year.
"The families think that it requires a public court hearing because what they want to establish here is not about money but accountability," Mr Cooper added.
