Marina Litvinenko's husband Alexander was poisoned with radioactive polonium 210 in December 2006 at a London hotel. She alleges that Putin ordered her husband's murder.
"Mr. Putin's agents killed my husband, a British citizen, in the center of the British capital and contaminated hundreds of innocent people with radioactive poison -- not to mention that he has rigged Russian election, suppressed free speech, beat protesters and jailed dissidents exactly the same way as Mr. Lukashenko did," Litvinenko told The Daily Telegraph.
Litvinenko referred to Alexander Lukashenko, the Byelorussian president considered to be "Europe's last dictator." Lukashenko was banned from attending this year's Summer Olympics; however, Litvinenko sees "no logic or consistency" in banning Lukashenko while Putin was allowed to attend.
Litvinenko called for Londoners to wear white ribbons, the symbol of Russian protest, when Putin arrives in London Thursday.
"I am sure that my husband, if he were alive, would have been among those protesters," Litvinenko said.