The footage is contained in a documentary the UK Ministry of Defence (MoD) released yesterday as Ukrainian tank crews completed their training.

Britain is gifting 14 Challenger 2 tanks to Ukraine together with depleted uranium shells, which Declassified revealed last week.

An MoD spokesperson told the media that the “impact to personal health and the environment from the use of depleted uranium munitions is likely to be low”.

But the decision to supply the ammunition sparked a furious reaction from the Kremlin, with Vladimir Putin pledging on Saturday to retaliate by moving ‘tactical’ nuclear weapons into Belarus.

The depleted uranium (DU) ammunition seen in the MoD documentary is marked “inert”, suggesting it could be a replica. A blue and silver training shell is visible next to it, an expert told Declassified. 

Doug Weir from the Conflict and Environment Observatory said: “The orange and black munition in the video appears to be an inert display version of the UK’s 120mm CHARM3 DU ammunition.”

CHARM3 is a technical term for Britain’s stockpile of depleted uranium shells. 

Weir added: “When DU munitions hit hard targets such as tanks or armoured vehicles, they fragment and burn, generating chemically toxic and radioactive DU particulate [microscopic particles] that poses an inhalational risk to people. 

“Managing DU contamination appropriately will be a further burden for Ukraine, in a conflict that has already generated serious pollution problems.”

The shells are shown spread out on a table with other types of ammunition, as Ukrainian tank crews listen to a lecture from US and British soldiers.

The presence of an American soldier at the training session could escalate tensions further, after the White House denied sending any of its own DU stocks to Ukraine last week.

The text on the UK military video states: “Instructors begin to familiarise Gunners, Loaders and Commanders with Challenger 2 ammunition types”.

Health impacts

Depleted uranium is standard ammunition for the tanks Britain is giving to Ukraine, despite long running concerns about its health and environmental impacts. 

It has been blamed for causing cancer and birth defects in Iraq.

Jack Watling, a researcher at the MoD-funded RUSI think tank, wrote in the Spectator yesterday: “I wouldn’t recommend Russian soldiers go to sleep cradling a depleted uranium round, or lick the tip of the ammunition – depleted uranium is still toxic.” 

He added: “But when Russian troops do come into contact with one of these projectiles, the fact that the uranium will be travelling at around 1,800 metres per second and burning up as it flies will be more concerning to any target than its radioactivity.”

UK Defence Secretary Ben Wallace said today: “It is truly inspiring to witness the determination of Ukrainian soldiers having completed their training on British Challenger 2 tanks on British soil.

“They return to their homeland better equipped, but to no less danger. We will continue to stand by them and do all we can to support Ukraine for as long as it takes.”