Families of four servicemen killed in Snatch Land Rovers in Iraq and Afghanistan are suing the Ministry of Defence for compensation, their lawyer said today.
The relatives argue that the lightly-armoured vehicles failed to protect their loved ones properly.
The fourth claim was served on the MoD's lawyers today by the sister and eight-year-old daughter of Private Lee Ellis, 23, from Wythenshawe, Manchester, who died in Al Amarah in southern Iraq in February 2006.
Jocelyn Cockburn, partner at London-based Hodge Jones and Allen solicitors, said these were the first claims to challenge the Snatch's vulnerability.
"Snatch Land Rovers are lightly armoured and designed to provide no more than limited protection against ballistic threats, mainly small arms bullets," she said.
"They provide little or no protection against improvised explosive devices (IEDs)."
The four cases will now be put on hold until the High Court rules on whether former defence secretary John Hutton was wrong to refuse a public inquiry into the use of the vehicles.
The claims are being brought for negligence and under Article 2 of the 1998 Human Rights Act, on the basis that the MoD failed to provide reasonable protection to save the soldiers' lives.
Ms Cockburn said the case relied on a landmark Court of Appeal ruling last week that British troops serving abroad are protected by human rights laws.
The other claims have been brought by the families of Marine Gary Wright, 22, from Glasgow, who died in Helmand Province in Afghanistan in October 2006; Lance Corporal Kirk Redpath, 22, from Romford, Essex, who died near Basra in Iraq in August 2007; and Private Phillip Hewett, 21, from Tamworth, Staffordshire, who died in Al Amarah in July 2005.
The Snatch Land Rover was originally designed as a cheap and quick way of transporting troops in Northern Ireland.
But it has been heavily criticised for failing to protect against roadside bombs following a series of deaths in Iraq and Afghanistan.
Conservative MP Patrick Mercer, a former Army colonel, has called for the Snatch to be withdrawn from service.