Cameron will meet Russian President Dmitry Medvedev and then hold separate talks with his hawkish mentor and predecessor Putin -- the current prime minister who may return for another six-year stint at the Kremlin in March. London officials said this would be the first contact a British minister or diplomat has made with Putin since a few months after the agonising death by radioactive poisoning of former KGB agent Alexander Litvinenko. Britain links the killing to another retired Russian agent named Andrei Lugovoi who allegedly wanted to remove a dangerous opponent with secrets to hide about Putin's past. Moscow refuses to extradite the suspect -- now a member of parliament -- and accuses London of having botched the investigation while using the case to discredit Russia. The breakdown in relations under successive Labour governments has been one of the most serious between Russia and any Western power in the past decade. Britain has suffered most from Russia's subsequent refusal to share intelligence on counter-terror operations and basic crime fighting data. But it has also slowed Russia's drive to innovate its economy through foreign direct investments and Moscow officials have more recently voiced a cautiously optimistic view of the rise of Cameron's Conservative Party. "More and more people, including politicians, understand that ideological obsession must give way to pragmatism and the search for balance of interests," the Russian foreign ministry said on the eve of Cameron's visit. Cameron will lead a large business delegation to Moscow that includes the embattled head of the BP energy giant, which recently lost a lucrative oil deal with the Russia state oil company and was subsequently raided by bailiffs. But any lobbying attempts will be accompanied by strong domestic pressure on the British prime minister to challenge Russia's rights record at the talks. "These concerns need to be addressed before business can truly flourish," four former British foreign ministers wrote in a letter published in the Sunday Times. The Kremlin appears resigned to the idea of Cameron bringing up Litvinenko's death and other democratic concerns. But it also stresses that it is up to Britain to move beyond these issues if it wants better ties. "I do not expect the Litvinenko issue to dominate," said Kremlin foreign policy adviser Sergei Prikhodko. "We do not plan to bring this issue up. There are more important topics." One issue likely to be on the table is Syrian President Bashar al-Assad's ruthless crackdown on the opposition. Russia has close ties with Syria and Moscow's refusal to support UN sanctions against its regional ally has frustrated Western diplomatic initiatives. A Kremlin source said only that "special attention" would be paid to the Libya and Syria crises. But there has been little indication from Moscow that its patience with Assad is running out. Cameron's visit to Russia is the first by a British prime minister since Tony Blair visited Saint Petersburg for a G8 summit in July 2006.