Poland has banned The Night Wolves biker gang backed by Russian President Vladimir Putin from entering the country.
The Night Wolves had planned to enter next week as part of a ride across Europe to commemorate the 70th anniversary of World War Two.
Poland’s PM Ewa Kopacz had called the plan a “provocation”.
The Night Wolves’ vice-president, Felix Chernyakhovsky, has insisted the bikers still intend to make the trip.
“Everything remains the same. We’re starting tomorrow as planned,” he told Interfax news agency.
Russia’s foreign ministry said it was “outraged” at Poland’s decision.
A Facebook page entitled “No to the Russian bandits’ ride through Poland” quickly gained support from more than 10,000 people.
Warsaw has been a strong critic of Moscow’s actions in Ukraine.
The Polish foreign ministry said three other Russian biker groups would be allowed into the country.
The ministry said it was notified of the group’s plans only on April 20, and without details of the route or number of participants.
It added that it had informed the Russian embassy in Warsaw that the lack of information meant “it could not ensure proper security for the participants”.
However, Russia’s foreign ministry said in a statement: “It is clear that the decision that was taken has a political motive.”
The Night Wolves intend to cross several countries, following a path taken by the Red Army in World War Two, with the aim of arriving in Berlin in time for May 9 Victory Day celebrations in Moscow.
The 3,720 mile road trip would take them through Russia, Belarus, Poland, the Czech Republic, Slovakia and Austria, before reaching Germany.