"This initiative is also likely to be part of a wider project to instil an ideology of patriotism and trust in public institutions in the Russian population," the ministry said on Sunday in its latest update on the war in Ukraine.
The ministry said the plans were a revival of a Soviet-era programme, discontinued in 1993, that included preparation for nuclear and chemical attacks, as well as a first aid course and rifle practice.
With the programme, announced by Russian Education Minister Sergey Kravstov earlier in November, Russian officials had attempted to revive the training in 2014 following Russia's invasion of Crimea in the hope of improving the quality of conscripts, the British ministry said.
It expressed the view that eight years later, "little has changed, and the quality of Russian conscripts remains poor, with low morale and limited training."
The British Defence Ministry has published information sourced from the country's intelligence services since the war began at the end of February with the aim of countering Russian reports and of boosting backing for Ukraine in the West.
Moscow accuses London of a campaign of disinformation.
