The European Union has criticised a travel ban imposed by Russia on 89 European citizens - many of whom are outspoken Kremlin critics - as "totally arbitrary and unjustified".
The list was revealed to European diplomats this week and includes past and serving parliamentarians and ministers who have openly criticised President Vladimir Putin and the war in Ukraine.
Military figures and secret service chiefs are also thought to be on the list.
European politicians who discovered they had been banned from travelling to Russia wore the badge proudly, as Brussels took aim at Moscow for the decision.
Beyond releasing the names of the blacklisted individuals to diplomats, Moscow has failed to provide "any other information on legal basis, criteria and process of this decision," the EU's foreign service said.
"We consider this measure as totally arbitrary and unjustified, especially in the absence of any further clarification and transparency," it said.
A spokeswoman for Britain's Foreign Office said there was no justification for the travel ban.
"If Russia's intention is to put pressure on the EU to ease sanctions then this is not the way to do it," she said.
A Russian foreign ministry official confirmed to Russian media that lists of banned individuals had been sent to EU states but declined to comment on the individuals themselves.
Among those listed is Uwe Corsepius, current secretary-general of the European Union council in Brussels, who is due to take over as foreign affairs adviser to German Chancellor Angela Merkel.
The document also includes Bruno Le Roux, the leader of French President Francois Hollande's Socialists in parliament, Britain's former deputy prime minister Nick Clegg and former Belgian premier Guy Verhofstadt, who heads the Liberal group in the European parliament.
Poland, which has been the sternest EU critic of Russia's policy towards Ukraine, had 18 names on the list.
"For some time we've seen that Russia is not necessarily trying to mitigate tensions but rather strengthen them," a spokeswoman for Poland's government told Reuters.
Last Monday, Germany protested to Russia over its refusal to let a conservative German politician, Karl-Georg Wellmann, who had called Russia a "warmonger" earlier this year, into the country.
Other countries with names on the list include Latvia, Lithuania, Estonia, Denmark, Finland, Sweden, Czech Republic, Romania, Bulgaria, Spain, and The Netherlands.
Blacklisted politicians were nevertheless proud about being banned by Russia.
"Those who try to censor us and make us scared for standing up for values deserve even more criticism. For me it's about being very committed to standing up for peace and freedom in Ukraine," one of those banned, Swedish MEP Anna Maria Corazza Bildt, told AFP news agency.
"I'm more proud than scared and this gives me more determination to continue... If the Kremlin takes me and my colleagues seriously it means we're doing a good job," the centre-right politician, married to Sweden's former foreign minister Carl Bildt, added.
A member of Russia's parliament on Sunday formally requested that the foreign minister, Sergey Lavrov, confirm and explain the list of the politicians who have been banned entry to Russia.
Russia has shared the list with European Union officials, but has refused to release the full list.
Dmitry Gudkov, the sole member of Russia's parliament who opposes the Kremlin, asked Lavrov to confirm the names and to state why they were included.