Poland’s prime minister has branded the plans by a group of nationalist Russian bikers to stage a “victory ride” from Moscow to Berlin later this month a “provocation”.

The Night Wolves are staunch supporters of President Vladimir Putin, and say they want to carry out the rally to commemorate 70 years since the victory over Nazi Germany in 1945, which Russia will celebrate on 9 May. The bikers plan to set out from Moscow on 25 April, and travel through Belarus, Poland, the Czech Republic, Slovakia and Austria before arriving in Berlin on 9 May.

Polish prime minister Ewa Kopacz said on Wednesday that the planned ride was a “provocative action” and raised the possibility that Polish border guards may not let the bikers into the country.

“To Berlin!” says a page on the biker gang’s website dedicated to the rally, in an allusion to the Red Army’s famous battle cry.

During their journey the bikers will visit war memorials, Auschwitz and Dachau death camps and Berlin’s Treptower Park, famous for its Soviet war memorial.

What makes the rally controversial is that the Night Wolves and their leader Alexander Zaldostanov, known as the Surgeon, have been vocal supporters of Russia’s policies in Ukraine. The Surgeon is from Sevastopol, and has repeatedly said he is delighted that the peninsula has become part of Russia. The Night Wolves put on a huge show in Crimea after the annexation involving bike stunts and people dressed as Ukrainians marching in the form of a swastika.

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The Surgeon is also one of the founders of the anti-Maidan movement, an initiative designed to stop any kind of street opposition to Putin in Russia. At the launch of the group, he said an alternative name for it could be “death to faggots”, and he has repeatedly claimed that the west is attempting to foment a coup inside Russia. In 2010 Putin rode a Harley Davidson when he met with the group at a rally in Crimea, adding to the Russian leader’s carefully crafted macho image.

The Surgeon is subject to US and Canadian sanctions for his support of Moscow’s seizure of Crimea from Ukraine last year.

But the bikers have insisted that their rally to Berlin is non-political and is aimed at honouring the graves of Soviet soldiers along the way.

“Of course you have to understand that there were Poles who fought and arrived with the Red Army to Berlin,” said the Surgeon in comments earlier this week to a Russian newspaper. “But there were also Poles who were the policemen in Jewish ghettos. Perhaps it’s their descendants who don’t like the idea of our rally today. But we don’t care if people don’t like it, we are not changing our plans.”

Vladimir Putin with the leader of the Night Wolves in Russia in 2011. Photograph: AP

Some Polish bikers have said the Russian group should be allowed to journey through the country, while elsewhere in the country there have been calls to block roads to stop the bikers from passing.

“The final decision on whether to allow them entry will be made by the border guards,” said Kowacz

It is unclear whether the bikers have visas in place to carry out the tour. The countries on their route are part of the Schengen visa alliance, but Poland said it had not issued visas, and a German interior ministry spokesperson told the Associated Press that the Night Wolves had not applied to Germany for visas.

“The responsible authorities will watch it very closely,” Germany foreign ministry spokeswoman Sawsan Chebli told the agency.