Members of the Russian delegation to the Organization for Security and Co-operation in Europe (OSCE) were denied British visas to attend a session in Britain next month.
A senior Russian lawmaker said on Wednesday that members of Russia's delegation had not secured British visas and would be unable to travel to the OSCE's annual parliamentary assembly in Birmingham in July.
The British embassy in Moscow said Russia's delegation to the OSCE was barred from entering the UK under sanctions imposed by London in response to Russia's invasion of Ukraine.
"All members of the Russian delegation are under sanctions in the UK for their role in destabilising Ukraine and undermining the territorial integrity, sovereignty or independence of Ukraine," the embassy said on Wednesday in a statement posted on the Telegram messaging app.
"These sanctions prohibit them from, among other things, travelling to the UK."
The OSCE is a Cold War-era multinational body designed to prevent and monitor conflicts in Europe. The annual meeting of its parliamentary assembly will take place in the English city of Birmingham on July 2-6.
The British Home Office (interior ministry) said earlier it was prioritising visa applications from Ukrainians and that there were "no restrictions or limitations for Russian nationals to work in the U.K. on long-term work visas".