Putin’s military chiefs are reportedly urging the Russian president to drop the term “special operation” which has previously been used for the invasion of Ukraine and instead declare war. The move would enable the mass mobilisation of Russians.

Putin has insisted on using the term “special operation” for the war in Ukraine since Russia launched its invasion on February 24.

Kremlin diplomats and Russia’s state-run media have been banned from using the word “war” to refer to the conflict as the Kremlin has insisted.

However, as the offensive has struggled to gain control in recent weeks, military officials are reportedly calling for Putin to declare war.

Mass mobilising Russians would bolster Moscow’s faltering war effort.

A source close to Russian military officials told The Telegraph: “The military are outraged that the blitz on Kyiv has failed.

“People in the army are seeking payback for failures of the past and they want to go further in Ukraine.”

Western officials have also suggested that Putin is preparing to declare war in the coming weeks as part of a final push in Ukraine.

Britain’s Defence Secretary Ben Wallace said on Friday the Russian leader is likely to announce a general mobilisation of the Russian population within weeks to make up for its military losses.

Mr Wallace said that Putin could use the upcoming Russian Victory Day parade on May 9 to make the move, on the day the country commemorates the USSR’s victory in World War 2.

Mr Wallace told LBC: “I would not be surprised… that he is probably going to declare on May Day that ‘we are now at war with the world’s Nazis and we need to mass mobilise the Russian people’.”

The Russian president is reportedly becoming increasingly desperate to show the invasion of Ukraine as a success following his military failures, including the abandoned assault on Ukraine’s capital, Kyiv.

Russia has been plagued by struggles on the battlefield, suffering logistical errors and heavy losses of military equipment and personnel, with around 15,000 troops estimated to have been killed in the conflict.

One Western official said there will be a desire in the Kremlin to have “some form of success narrative to be able to give to the population” while its troops struggle to make gains in the east of Ukraine.

According to other Western sources, there has been no suggestion so far that the Kremlin is preparing to shift its narrative on the Ukraine invasion, however the situation could change in the coming days.

A number of prominent voices related to the Russian military have voiced their frustration at Russia’s military failures in recent weeks and called for Putin to step-up his offensive on the country.

Alexander Arutyunov, a retired Russian commando and usually one of the country’s most popular pro-Kremlin bloggers, posted a video online voicing his discontent.

Addressing Putin, he said: “Vladimir Vladimirovich, can you please make up your mind: are we fighting or are we playing around?”

Igor Girkin, a retired military intelligence officer known for his strong anti-Ukraine views, also lashed out at the Kremlin online.

After reeling off a list of the Kremlin failures since the invasion began, including the sinking of the flagship of its Black Sea fleet last month, he said: “What else has to happen before the dwarves in the Kremlin realise they are in an all-out, harsh war and start to act accordingly?”

Declaring an all-out war with Ukraine would see the Kremlin impose martial law and mass mobilisation.

Mobilisation would mean Russia would have to call up reservists and keep military conscripts beyond their one-year term.

The imposition of martial law, which has reportedly been feared by Russians since the start of the conflict, would close the country’s borders and nationalise large swathes of the country’s crippled economy.

The move would destroy any last semblance of normality in Russia, which has been choked by Western sanctions and cut off from the international community over its atrocities in Ukraine, where Putin has been accused of war crimes.