Patriarch Kirill will visit the Queen’s residence this week in an aim to “strengthen mutual trust” between Russia and Britain, which marks his first visit for many years.
But Ukraine’s ambassador to the UK, Natalia Galibarenko, said the invite ran the risk of legitimising Russian aggression in the war-ravaged country, which Kirill has publicly supported.
She added: “Patriarch Kirill is a Krenlim mouthpiece.”
Kirill is a strong supporter of Russian President Vladimir Putin and once described him as a “miracle of God”.
He previously praised Russia’s actions in Syria as a holy war and of Russian action in Ukraine, saying the people have a “right to be united”.
Relations between the West and Russia are currently at boiling point over Putin’s actions in the Syrian city of Allepo.
Boris Johnson said he would like to see a protest against the bombing of Allepo, which has become the most high-profile battleground in the country’s five year civil war.
But Moscow played down the claims they are responsible for the bombings saying it was “Russophobia hysteria”.
The Foreign Office brushed off Ms Galibarenko’s criticism saying the Queen’s visit was part of her supreme governor of the Church of England role and it was “appropriate to recognise shared history and links”.