President Vladimir Putin has warned that Russia’s “foes abroad” are preparing to interfere in the country’s September general election.
He told the FSB security service that such attempts must be thwarted.
He also said the activities of more than 400 foreign intelligence agents had been foiled in Russia in 2015.
Moscow has long accused the West of trying to influence the poll through encouraging mass protests – a claim denied by US and European officials.
Addressing top FSB officials in Moscow, President Putin said: “Unfortunately, our foes abroad are getting ready” for the parliamentary elections scheduled for 18 September.
He said the techniques were well-known and urged the security service to “suppress any attempts at foreign influence”.
“This is a direct threat to our sovereignty,” Mr Putin warned, adding that the FSB must work “assiduously” to defend Russia’s interests.
Russia blames the West for political interference in neighbouring Ukraine and Georgia, where street protests – also known as “colour revolutions” – led to the ouster of political leaders in recent years.
The US and EU deny this, accusing the Russian authorities of harassing the opposition and stifling the freedom of speech.
Relations between Moscow and the West have deteriorated since Russia’s annexation of Ukraine’s southern Crimea peninsula in 2014 and its alleged support for pro-Russian rebels in eastern Ukraine.
Both the US and the EU have imposed sanctions against Russia, despite Moscow’s denial of any involvement in the Ukraine crisis.
Earlier this month, Russian Prime Minister Dmitry Medvedev warned that strains between Russia and the West had pushed the world “into a new cold war”.