At least £381 million has been spent overhauling British armoured vehicles, new figures have revealed, amid concerns over potential cuts to the programme.
Lockheed Martin was hired six years ago to overhaul and fit new gun turrets to Britain's ageing fleet of Warrior infantry fighting vehicles, which have served in the Gulf, Bosnia and Iraq.
Up to 380 new Warriors were to be upgraded under the original plans, with the vehicles forming the backbone of two armoured infantry brigades planned as part of a reorganisation of the army.
However, The Times speculated last month that one of these brigades could be disbanded with hundreds of its vehicles scrapped to cut costs.
Ministry of Defence documents forecast that the Warrior upgrade is a year behind schedule, with the programme incurring extra costs as a result of delays.
The £381m bill for Lockheed Martin's Warrior programme represents the costs to the end of July and was confirmed following a Freedom of Information request by the Press Association. The MOD was unable to confirm how the bill compared with the project's original budget.
A review of the defence spending programme is currently underway, which has led to speculation over cuts to the Royal Marines and the Navy's amphibious assault vehicles.
Analysts now speculate that the Warrior programme could be under threat too.
Trevor Taylor, a research fellow at the Royal United Services Institute think tank, said: "Given the MOD's apparent financial problems, anything is going to be subject to extensive scrutiny within head office if it is not part of the nuclear programme, not actually under contract, and looks technically problematic."
Francis Tusa, editor of newsletter Defence Analysis, said: "If they cut one whole armoured infantry brigade, that means you have two to two-and-a-half battalions fewer Warriors.
"You then have to amortise the development across a smaller number of vehicles, which means the cost of the kit goes up.
"That will be the next one coming out in a major projects report in three years' time.
"How come the vehicle is more expensive? You're amortising what was meant to be a 500 vehicle over 300."
An MoD spokesman said of the costs incurred so far: "This money has been used to develop state-of-the-art upgrades and demonstration vehicles for the Warrior platform as we look to enhance it for the future and boost the army's capabilities.
"We are contributing to the cross-government review of national security capabilities and looking at how we best spend our rising defence budget to protect our country in the face of intensifying threats, but any discussion of the options is pure speculation."
A Lockheed Martin spokeswoman said it had met all its contractual obligations. She added: "The Warrior Capability Sustainability Programme will deliver vital, battle-winning capability to the British Army and sustain hundreds of highly skilled UK jobs, and we have invested more than £100 million in our site to develop a unique, state-of-the-art manufacturing facility to meet our commitments on this programme."
Labour's Kevan Jones, a former defence minister, said: "Ministers need to urgently explain how £381 million has already been spent on a vehicle that might now only be deployed in very limited numbers.
"The government's attempts to balance the books of the defence budget are becoming increasingly chaotic."
A £1.4 Billion Warrior Upgrade Programme
The Warrior Capability Sustainment Project (WCSP) is the major part of the armoured infantry 2026 programme.
The £1.4 billion upgrade plan is to enhance and extend the life of a British military stalwart.
First brought into service in 1988, the Warrior can hold six infantry troops and has a 30mm gun.
In 2011, Lockheed was charged with overhauling the vehicle’s turret, electronics and armour, extending its out-of-service date from 2025 to 2040.
The MOD's major projects portfolio data, published this summer, put the overall cost of the armoured infantry programme at £1.613 billion, which includes some of the expected in-service costs of the Warrior.
But the report says the Warrior upgrade project now has increased forecast costs "as a result of delays in the demonstration phase", with a focus in 2016/17 on stabilising the programme's costs.
The MOD report also downgraded the Warrior's delivery forecast to "amber/red" in light of "a number of challenges".
It said the MOD now forecasts a "12-month slip to equipment delivery", with negotiations with Lockheed Martin key to addressing this.