Ukraine LIVE: Putin activates '50 sleeper agents' to start attacks on UK infrastructure

In its latest intelligence update the Ministry of Defence said both Russia and Ukraine have continued to conduct heavy artillery bombardments in the north, east and south of the Sieverodonetsk pocket but with little change in the front line.

It added: “Combat units from both sides are committed to intense combat in the Donbas and are likely experiencing variable morale.

“Ukrainian forces have likely suffered desertions in recent weeks, however, Russian morale highly likely remains especially troubled. Cases of whole Russian units refusing orders and armed stand-offs between officers and their troops continue to occur.”

The statement continued by saying that Russian authorities would likely struggle to bring legal pressure to bear on military dissenters as they are hampered by the invasion’s official status as a “special military operation” rather than as a war.

It added: “Drivers for low Russian morale include perceived poor leadership, limited opportunity for rotation of units out of combat, very heavy casualties, combat stress, continued poor logistics, and problems with pay.

“Many Russian personnel of all ranks also likely remain confused about the war’s objectives. Morale problems in the Russian force are likely so significant that they are limiting Russia’s ability to achieve operational objectives.”