The Moscow Patriarchate deplores the ban in Great Britain on wearing religious symbols in the workplace, describing it as a manifestation of totalitarianism.
"Those Western liberals who are actually forcing totalitarian regime standards on free people are making a big mistake," said Metropolitan Hilarion, head of the Moscow Patriarchate Department for External Church Relations, on Rossiya 24 television.
These people have not gone through reprisals against the Church "and therefore they do not know what it feels like when your cross is being ripped off your neck," he added.
The Metropolitan said he had had an experience of living in Britain and he could see "liberal and Anarchist patterns spreading fast in the public space."
Recently, British courts have given employers the right to fire workers who wear crosses on their clothes.
The British government wants to defend the ban on wearing crosses at work in the European Court of Human Rights, which is set to examine four cases brought by British citizens.
They include that of Nadia Eweida (pictured), a British Airways employee who was suspended for wearing a cross on a plane, in violation of company policy.
Ms Eweida has taken her case to Strasbourg. For David Cameron's government, which backs the airliner, wearing a cross is not a compulsory element of the Christian faith.
"The introduction and even a discussion of such standards looks like a symptom of some madness or extreme moral decay," Hilarion said, adding that believers will never put up with this and will fight.
Archpriest Mikhail Dudko, the sacristan of the Russian Assumption Cathedral in London, said recently that one of his parishioners, a woman, lost her job for wearing a cross at work, even though it was not visible.