"I congratulate MI6 and all British secret services with the loudest flop in their history," he told the Associated Press news agency.
He said he would fight his accusers "in a way that is many times harder and more painful".
Lugovoi, 43, who is running for parliament in the December 2 elections in Russia, said he expects the British government to use the anniversary of Litvinenko's death to renew calls for his extradition.
A seat in parliament would give Lugovoi legal immunity, but he said he was running out of patriotic duty.
Vladimir Zhirinovsky, head of the ultra-nationalist Liberal Democratic Party of Russia, placed Lugovoi's name among the top three on the party list of candidates for parliament.
"British intelligence services are behind this," Lugovoi said.
"So far,they have no proof of any kind, and everything about the Litvinenko case is politicised. I'm sure they will not provide anything to anyone, and will keep the issue hot to further discredit Russia on the international scene."
Polonium poisoning
Litvinenko, a former state security agent who had settled in London, died in November 2006, in a London hospital from a massive dose of polonium 210, a radioactive isotope.
On his death bed, Litvinenko accused Vladimir Putin, the Russian president, of ordering his murder.
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Last year, from his death bed Litvinenko
accused Putin of ordering his murder [AFP] |
The Kremlin said the allegation against Lugovoy was nonsense and refused a British request for Lugovoy's extradition.
The case triggered the worst diplomatic spat between Britain and Russia since the end of the Cold War.
The Russian constitution prevents Lugovoi from being handed over, so he is not concerned about what British officials and Litvinenko's friends might demand.
"Several times, Russia's law enforcement system and I have asked the British to provide proof and the evidence against me," he said.
Plans dismissed
As well as dismissing the British authorities, Lugovoi discredited plans by Litvinenko's widow, Marina, to prosecute him in the European Court of Human Rights.
A former bodyguard for senior government officials, Lugovoi had a business meeting with Litvinenko on the day he first fell ill.
Litvinenko, himself a veteran of Russia's security agencies, co-authored a book accusing former colleagues in Russia's Federal Security Service of involvement in a series of deadly bombings in 1999.
He was granted political asylum in Britain in 2000.
Before his death, Litvinenko was investigating the murder of Anna Politkovskaya, a journalist and critic of Putin.