This story was updated June 3, 2021, at 3:40 p.m. EST with a statement from General Dynamics UK.

LONDON — British Army attempts to modernize its armored fighting capabilities have taken a new hit with reports that the General Dynamics UK-built Ajax reconnaissance vehicle has encountered significant design problems.

British newspaper Daily Telegraph cited a leaked document outlining issues such as excessive vibration, which had required the Army to impose speed restrictions on the vehicle and limits on the time crews could operate them.

At one point the Army was forced to pause trials on the vehicle, said The Telegraph.

Media reports of vibration and other issues impacting the program first surfaced several weeks ago but the latest report has given more detail.

News of the problems with Ajax comes just weeks after the government axed a multibillion-dollar program with Lockheed Martin UK to upgrade Warrior infantry fighting vehicles.

The program, years late and over budget, was ready to enter the production phase when the Ministry of Defence pulled the plug on the upgrade.

The decision, announced as part of the government’s integrated defense and security review in March, was the latest in a catalogue of armored fighting vehicle procurement issues which have plagued the British military for years.

The leaked government report, expected to be published next month, is reported by the Telegraph to say the vehicles cannot reverse over obstacles more than 20 centimeters high, that personnel must wear noise-cancelling headphones when operating them and undergo ear tests afterwards, and that the Household Cavalry Regiment “cannot conduct effective collective training” in them.

In a statement, the MoD confirmed trials had been halted but said test work had now resumed “with appropriate safety measures in place.”

“We are committed to the Ajax program which will form a key component in the Army’s modernized warfighting division, with current plans for initial operating capability scheduled for summer 2021,” a ministry spokesperson said in a statement. “The MoD can confirm that some training on the Ajax family of vehicles was paused as a precautionary measure.”

“This is a normal measure for the demonstration phase of projects; an investigation, incorporating trials, is being carried out jointly with the manufacturer. It is inappropriate for us to comment further at this time,” the spokesperson added. “The health and safety of our personnel is of the utmost importance and we are committed to providing a safe working environment.”

One senior defense source, who spoke to Defense News on condition of anonymity, said Defence Secretary Ben Wallace prioritized an assessment of the Ajax program when he came into office.

“It was no secret that the program, that was originally contracted in 2010 and 2014, has had problems, which is why the MoD has intensified scrutiny and work to rectify the issues,” the source added. “The Army, General Dynamics and the MoD [are] now engaged in an intensive round of assessments and rectification work to resolve any outstanding issues.”

General Dynamics UK told Defense News that it is working with the Army and ministry to complete demonstration phase activities.

“Recent trials have confirmed many of the required capabilities across the AJAX Family of Vehicles, including operations across the full range of speed and reverse step obstacle climb,” the company said. “A small number of remaining issues are being reviewed and closed out in partnership with the British Army and Ministry of Defence ahead of Initial Operating Capability.”

The company assured the parliamentary Defence Committee recently the problems had been largely resolved.

In March the committee published a report on the state of armored fighting vehicle capabilities here. Titled, “Obsolescent and Outgunned: The British Army’s Armoured Vehicle Capability,” it didn’t make for happy reading.

Talking about the Ajax program, the committee said: “The Ajax program, which is now seriously delayed, is yet another example of chronic mismanagement by the MoD and its shaky procurement apparatus.”

The committee said it was “particularly worrying, as Ajax is fundamental to the establishment and deployment of the Army’s new Strike Brigades, which are intended to be a key part of its future order of battle.”

General Dynamics was selected ahead of the BAE Systems CV-90 in 2010 to develop a new reconnaissance vehicle for the British based on its ASCOD platform already used by the Spanish and Austrian military.

That subsequently resulted in a £3.5 billion production deal with the British MoD in 2014 to manufacture 589 vehicles in several different configurations to form a key element of Army transformation plans. The principal variant is an ISTAR vehicle equipped with the turret and a revolutionary 40 mm CTAI cannon.

The program is years behind schedule with deliveries previously due to commence in 2017.

To date only around 14 of the ARES troop carrying variant have been delivered.