Five armed Reaper drones purchased to provide UK troop support in Afghanistan have reportedly not taken to the skies, and will likely remain grounded when British forces officially pull out.

The new drones were bought as an urgent requirement and announced in 2010 by Prime Minister David Cameron and then-Defense Secretary Liam Fox during a trip to Afghanistan.

But more than three years after the original announcement and months before British forces are scheduled to leave Afghanistan, the drones have yet to be deployed, the Bureau of Investigative Journalism reports.

The delay has deprived British ground forces of a “significant increase in air surveillance” which could protect them from threats such as roadside bombs.

On Thursday, Margaret Hodge, chair of the Public Accounts Committee, said the report “beggars belief.”

“These aircraft were meant to be supporting soldiers on the front line and now we learn that they may play no active role in Afghanistan at all,” she said. “This appears to be another procurement shambles that has let down our troops. The question the MoD [Ministry of Defence] needs to explain is what they intend to do with these aircraft now.”

Shadow Defence Secretary Vernon Coaker blamed MoD inefficiency on Cameron’s coalition government.

“While armed forces families are facing a cost-of-living crisis, David Cameron squanders millions of taxpayer pounds on dud equipment that will never be used,” he said.

The Liberal Democrat MP Sir Bob Russell, a member of the Commons Defence Select Committee, who represents the Essex army town of Colchester, said “This is obviously of concern. The Ministry of Defence needs to explain why there are delays and what they are doing to remedy matters.”

The RAF’s 39 squadron currently controls five Reapers from Creech Air Force Base in Nevada, USA.

In December 2010, it was announced that the UK’s Reaper capability would be doubled to 10 airframes, sustained until 2015. The 135-million-pound (US$227 million) funding increase went towards both the purchase of the drones, plus four ground control stations from the US government. The drones were slated to be based in Afghanistan.

“This transition will see us bring Reaper mission control to the UK, make more efficient and effective use of our resources in exploiting this growing capability and enable the operation of significantly more Combat Intelligence Surveillance Target Acquisition and Reconnaissance aircraft over Afghanistan 24 hours a day,” the then-chief of the air staff, Air Chief Marshal Sir Stephen Dalton, said at the time.

However, delivery of the aircraft from the manufacturer, US defense company General Atomics, was delayed, as a shipment of Reapers for the US Air Force (USAF) took precedence. The British Reapers were then beset by a series of technical difficulties.

The aircraft finished their testing phase in February and have now been sent to Afghanistan, where they are being rebuilt and tested. An MoD spokesman told the Bureau they are expected to start flying missions in the “near future.”

“A late notice engineering change to the new production aircraft did delay the completion of acceptance testing. That work is now complete and delivery of the five new aircraft to the UK MoD is complete,” the spokesman added.

Meanwhile, of the five operational Reapers in the UK arsenal, one is out of action for “corrective measures.”

A MoD spokesman told the Bureau the USAF has loaned the RAF one of its Reapers to fill in.

It was revealed in 2013 that members of the Royal Air Force embedded within US forces had carried out 2,150 missions in Afghanistan, Libya and Iraq. However, the MoD did not divulge any specifics on the nature of the missions or the weapons that were used.

In response to a freedom of information request by British rights group Drone Wars UK, the Ministry of Defense said in February it had launched 39 missile strikes from unmanned US craft in Afghanistan. It was first time the MoD had admitted to using American craft in conflict zones to carry out strikes.

“Of the 2,150 missions flown by UK personnel, there were 271 missions in Afghanistan when UK personnel utilized a US Reaper, as a UK Reaper was unavailable. During these missions, UK personnel released 39 weapons. I am withholding information about weapons released by UK personnel embedded with the United States Air Force on operations in Afghanistan and Libya under Section 27 [of the Freedom of Information Act],” said a statement from the MoD at the time.

In response to the statement from the MoD, rights group Drone Wars UK said the lack of transparency was a testament to the “secrecy surrounding the use of armed drones.”