Vladimir Putin hit out at Downing Street for blaming "all their mortal sins" on Russia, saying undue accusations have been placed at Moscow's door for everything from Brexit to the Skripal poisoning and the downing of MH17.
He scoffed at suggestions that Russian hackers have been interfering in state affairs, saying this was "not in line with our policy”.
Russia’s leader branded accusations by Britain as “tosh” and warned the UK it was worsening its relationship with Moscow.
It came just hours after defence secretary Gavin Williamson gave a grim assessment of Russia’s threat to Britain.
The Ministry of Defence chief warned the Putin’s regime “continues to challenge us in every domain”.
Putin said: "They now blame Russia for Brexit... again, tosh.
"We have nothing to do with it whatsoever. This is the inner matter of the UK.
"And I guess we can suspect that those who wanted the UK to leave the EU are Russian agents.
"If they want to worsen their relationships with Russia they can blame all their mortal sins on us and this is actually the case nowadays.”
Putin also rubbished claims it was a Russian missile that downed passenger plane MH17 over Ukraine.
Mr Putin was speaking to reporters on the margins of the St Petersburg International Economic Forum.
International investigators concluded earlier this week that a Russian military unit was responsible for firing the missile which brought down Flight MH17 over war-torn eastern Ukraine nearly four years ago.
Britain has now backed international calls by the likes of the Netherlands and Australia for Moscow to be held accountable for the event - which killed all 298 people on board.
In a statement, Foreign Secretary Boris Johnson said the incident - which claimed the lives of 10 British nationals - was "an egregious example of the Kremlin's disregard for innocent life".
But Mr Putin's spokesman Dmitry Peskov rejected the findings, saying Russia had been barred from taking part in the investigation and did not trust its results.
The Russian defence ministry said the missile involved "more than likely" came from Ukrainian arsenals.
Russia and the West have become increasingly divided over the Skripals, the war in Syria, military buildup in eastern Europe and the annexation of Crimea.
Williamson warned “old threats’ were returning in a chilling throwback to the Cold War.
He said: "Russia has turned a blind eye to chemical carnage in Syria while using cyber attacks to disrupt governments and undermine democracy.
"We have to adapt to meet the intensifying threat.”
Royal Navy chiefs rolled out supersonic missiles this week to help defend from the threat of Russia.
