Nikolai Patrushev, who heads the Federal Security Service, the main KGB successor agency, also claimed that foreign spies were working to foment discontent in Russia in the run-up to December's parliamentary elections and the presidential vote next spring.
Patrushev is a longtime ally of President Vladimir Putin, and his comments reflect deeply entrenched suspicions of Western intentions in the Kremlin's inner circle amid a cold spell in Russia's relations with the West. Putin himself is a 16-year KGB veteran and former chief of the Federal Security Service, known as the FSB.
"Politicians thinking in the categories of the Cold War still retain their influence in a number of Western nations," Patrushev told the weekly Argumenty i Fakty. "They have claimed credit for the collapse of the Soviet Union, and they are hatching plans aimed at dismembering Russia. They are viewing special services and their organizations as an efficient instrument for their implementation."
Patrushev said that foreign spies were focusing their efforts on gathering information related to Russia's elections. "They are trying to influence protest feelings and demonstrations in Russia."
He singled out Britain's Secret Intelligence Service, or MI6, saying its agents "aren't only gathering intelligence in all areas, but they are also trying to influence the development of the domestic political situation in our country."
Russian-British relations have been sliding, and they were strained further by last November's poisoning death in London of former Russian security agent Alexander Litvinenko. Litvinenko, a fierce Kremlin critic given asylum in Britain, accused Putin on his deathbed of being behind his polonium poisoning - charges the Kremlin has angrily denied.
Russia has rejected British demands for the extradition of the sole suspect in Litvinenko's murder, former KGB officer Andrei Lugovoi, who met with Litvinenko in a London hotel bar the day he fell ill. Putin dismissed the extradition demands as a relic of British "colonial thinking."
Patrushev said that his agency had learned how to counter British intelligence.
"We know both its strong and weak points," he said. "Since the times of Elizabeth I, (MI6) agents have been guided by the principle of the ways justifying the means. Money, bribery, blackmail, exemption from punishment for crimes committed are their main recruitment methods."