David Cameron is expected to become the first senior UK official in four years to hold talks with Vladimir Putin when he visits Russia in a trip designed to soothe troubled relations between the two countries.
Whitehall officials have admitted there has been no high-level contact with the former president since 2007, but it is hoped the meeting will begin to rebuild the bridges that broke down following the murder of Alexander Litvinenko.
The Prime Minister will also hold talks with President Dmitry Medvedev as he makes the first prime ministerial visit to Moscow for six years next week.
Ties between the two countries nosedived in 2006 following the murder of Mr Litvinenko in London.
The UK authorities identified former KGB agent Andrei Lugovoy as a suspect in the poisoning of the dissident using radioactive polonium-2010 - but Moscow blocked his extradition.
The diplomatic stand-off led to tit-for-tat expulsions, the closure of some British Council offices and reduced security co-operation.
There has been a slow recovery in relations since the less combative Mr Medvedev took over the Kremlin in 2008.
But Mr Putin, currently prime minister, is expected to seek the top job again in elections next year - raising fears that UK-Russia links could enter the deep freeze once more.
It is understood Mr Cameron will bring the Litvinenko case up during discussions with Mr Medvedev.
However, diplomats are optimistic the issue has been compartmentalised and will not get in the way of a series of major trade deals.
