As the US and UK prepare to lift their restrictions on Ukraine using long-range missiles against targets inside Russia, Andrew Marr speaks to Vladimir Putin's former advisor, Sergei Markov, to find out how Russia could respond.

Putin has already issued a strong warning to the West about doing so and that Moscow would see that as “direct participation” by Nato countries in the war in Ukraine.

Britain and France have already 'Storm Shadow' missiles to Ukraine - but at the moment, Ukraine can only use them on targets within their own borders.

British Prime Minister Keir Starmer and US President Joe Biden will discuss whether to let Ukraine use these missiles in Russia, in what may prove to be their last meeting before the US election.