A former British diplomat in Russia has said “nothing much” surprises him about the country.

John Cummins spoke at Buckingham Palace after being awarded a CMG at an investiture ceremony on Thursday.

He told the Press Association: “In a way nothing much surprises me about Russia, but I watch it now as an observer from outside, and really my main thoughts are for the people who are trying to deal with and manage the problem because I know how difficult it is.”

Mr Cummins’s comments come as Moscow warned it will expel British diplomats “soon” after the Prime Minister announced the biggest expulsion of Russian embassy staff since the Cold War.

The former consul-general in Moscow said he is following the news of the nerve agent attack on Sergei Skripal “with great interest”.

He said: “It’s quite difficult in a way because you feel part of something, and it has been your life and then you’re on the outside watching it on the Today programme.”

Mr Cummins was working for the Foreign and Commonwealth Office in Russia when Chechen rebels seized a Moscow theatre in 2002.

More than 100 people died in the Dubrovka theatre siege, an incident Mr Cummins was heavily involved in as a diplomat.

He said: “That was a week of my life that I won’t forget. Not something I would like to repeat, but it was an occasion when you felt that you were really doing something that mattered.”

Mr Cummins, who has retired, was posted to Moscow for three-and-a-half years.

He was made a companion of the order of Saint Michael and Saint George by the Prince of Wales.