Uefa has given Szymon Marciniak the go-ahead to referee next Saturday’s Champions League final after he issued a lengthy apology for appearing as a main speaker at an event in Poland organised by a far-right politician. Szymon Marciniak said he “was gravely misled and completely unaware” of the affiliations of the Everest event which was established and promoted by Sławomir Mentzen, the leader of the Confederation party. Mentzen is widely known for launching the political slogan “We stand against Jews, gays, abortion, taxation and the European Union”. In 2021 he made international headlines as the producer of a beer named White IPA Matters, which mocked the Black Lives Matter movement. “I had no knowledge that [the event] was associated with a Polish extreme-right movement. Had I been aware of this fact, I would have categorically declined the invitation,” Marciniak said, in a statement issued through Uefa. It comes after the Guardian disclosed that Uefa had launched an inquiry into Marciniak’s participation at the event. European football’s governing body said it had accepted the apology and is to allow Marciniak to referee the Uefa Champions League final between Manchester City and Internazionale on 10 June at Atatürk Olympic Stadium, in Istanbul. On 29 May, Marciniak attended a gathering, under the title “Everest”, which was billed as a networking event complete with a beer drinking session. Anti-racist activists said it was an attempt to gain political support. Mentzen, who also buys and markets beer, told one journalist in the run-up to the event it would be a different type of conference. “The atmosphere will be closer to a rock concert, a boxing gala than a lecture hall,” he was quoted saying. The far-right politician, who reportedly spoke for an hour at the event, achieved notoriety in 2019 when he addressed a rally of the Confederation, which is formed from extremist and nationalist parties and social movements. He told supporters: “We don’t want the Jews, the homosexuals, abortion, taxes and the European Union.” Mentzen’s brewery produced the beer White IPA Matters two years ago, accompanied by an advertisement showing a black barman drinking it in a bar decorated with Confederate flags, which sparked hundreds of complaints. Marciniak is considered one of the most highly rated international referees of his generation. He officiated the 2022 Fifa World Cup final between Argentina and France in December in Qatar, and the 2018 Uefa Super Cup between Real Madrid and Atlético Madrid. The statement said: “I hope this statement will find its way to all those concerned, particularly the individuals who were rightfully alarmed and disappointed by my participation in the ‘Everest’ event organised in Katowice on 29 May 2023. I want to express my deepest apologies for my involvement. “Upon reflection and further investigation, it has become evident that I was gravely misled and completely unaware of the true nature and affiliations of the event in question. I had no knowledge that it was associated a Polish extreme-right movement. Had I been aware of this fact, I would have categorically declined the invitation. “It is important to understand that the values promoted by this movement are entirely contrary to my personal beliefs and the principles I strive to uphold in my life. I am deeply remorseful for any perception that my participation may have contradicted them. “As a professional deeply committed to the game of football, I want to emphasise my unwavering support for the values championed by Uefa, particularly inclusivity and respect for all individuals regardless of their background. “These principles lie at the very core of the spirit of football and align seamlessly with my personal beliefs. Moreover, I wholeheartedly condemn any form of hate, discrimination, or intolerance, as they have no place within the sport or society as a whole. “I also want to highlight my commitment to combating discrimination in football. I was among the first referees in the world, and certainly the first in my country, to apply the ‘three-step procedure’ in response to a serious discriminatory incident during a match in Poland. “Moving forward, I pledge to be more vigilant in scrutinising the events and organisations with which I associate myself. I am committed to learning from this experience and ensuring that such lapses in judgment do not occur in the future. “Lastly, I extend my sincere apologies to the clubs, players, fans, colleagues, officials and organisations who place their trust in me.” The Uefa inquiry into Marciniak’s involvement was undertaken by its chief of football, Zvonimir Boban, a former Croatia midfielder, and its chief refereeing officer, Roberto Rosetti. It said Marciniak will fulfil his role as the referee for the Champions League final. The anti-racist organisation Never Again, which first exposed Marciniak’s attendance at the event, said it accepted his apology.