Britain's defense ministry said that Russia has likely "deployed the vast majority of reservists," and could be forced to "scale back objectives." It said that the "harsh realities" of service is descouraging volunteers.

The British Ministry of Defense said in an intelligence update on the war in Ukraine that recruitment from Russian prisons has decreased since late last year.

"Data from the Russian Federal Penal Service had already suggested a drop-off in the rate of prisoner recruitment since December 2022," it said.

"News of the harsh realities of Wagner service in Ukraine has probably filtered through to inmates and reduced the number of volunteers," the ministry surmised.

The head of Russia's Wagner mercenary group, Yegveny Prigozhin, announced on Thursday that the group had ended its prison recruitment scheme. The UK Defense Ministry said that this may have been caused by "direct rivalry between the Russian Ministry of Defence and Wagner." 

"The regular Russian military has likely now also deployed the vast majority of the reservists called up under 'partial mobilization,'" the ministry said.

"The Russian leadership faces the difficult choice of either continuing to deplete its forces, scale back objectives, or conduct a further form of mobilization," the ministry said. On Friday, Prigozhin advocated for a clarification of Russian war aims in an interview for a Russian military correspondent.

DW