Alexander Yakovenko said the embassy was "shrinking" and questioned whether the UK wanted "an adequate Russian diplomatic presence".
He also criticised the prime minister and foreign secretary for giving what he said were "anti-Russian statements".
The Foreign Office said there was no policy to delay visas.
Mr Yakovenko said Russia did not have enough diplomatic staff in London because as people returned home or went on to other postings, visas for their replacements were not being issued.
