Polish Member of the European Parliament Dominik Tarczyński has accused the British government of behaving like a communist regime after he was denied entry into the UK ahead of a right-wing march planned for Saturday in London.

In a post published on X, Tarczyński said: “This is what communism looks like in the 21st century” after Keir Starmer’s Labour government prevented him from entering the country to address the “Unite the Kingdom” rally organised by anti-immigration activist Tommy Robinson.

The Polish politician vowed to take legal action, writing: “Starmer will be sued by me. Not the government, not the Home Office, but Starmer personally.” He added: “Once you lose the next election, communist, we’ll meet in court!”

The incident is likely to add to criticisms that the Labour government is restricting political speech. Tarczyński is a member of Poland’s main opposition Law and Justice (PiS) party and is affiliated with the European Conservatives and Reformists Group (ECR), one of the largest conservative blocs within the European Parliament.

Former UK prime minister Liz Truss called the action “shocking” and warned Keir Starmer that he “wouldn’t be able to do this” if he got his wish to rejoin the EU.

Starmer has faced growing political pressure in recent weeks following internal Labour disputes and a disastrous set of local election results last week. Close to 100 Labour MPs have now publicly called for his resignation, while several ministers have resigned, calling for him to stand down.

Other right-wing commentators who have been banned from the UK ahead of Saturday’s march include Ada Lluch, Eva Vlaardingerbroek, Joey Mannarino, and Valentina Gomez.