The European People's Party (EPP) said on Friday it was cancelling a planned event in Naples due to criticism of Ukraine by former Italian Prime Minister Silvio Berlusconi, whose Forza Italia party is an EPP member.
"Following the remarks by Silvio Berlusconi on Ukraine we decided to cancel our study days in Naples. Support for Ukraine is not optional," EPP President Manfred Weber wrote in a tweet.
The EPP's European parliamentary lawmakers had been due to gather in Naples in June to discuss strategy.
Berlusconi said on Sunday that if he were prime minister he would not seek a meeting with Ukrainian President Volodymyr Zelenskiy because he blamed him for the war with Russia and judged his behaviour "very very negatively."
The former Italian prime minister, 86, reacted with dismay to the EPP's decision.
"With the world on the brink of a nuclear war between Russia and NATO countries, I get criticised because I ask that, together with the support for Ukraine ... negotiations should be immediately launched to achieve peace," he wrote on Facebook.
He added that this should be "immediately put on the agenda of the EPP's next meetings."
Berlusconi often boasted of his friendship with Russian President Vladimir Putin until Moscow's invasion of Ukraine, and in September he said Putin had been pushed into the war and had only wanted to put "decent people" in charge of Kyiv.
Weber's decision triggered a chorus of dissent from Forza Italia's top brass.
"Berlusconi is Forza Italia and Forza Italia is Berlusconi," tweeted Deputy Prime Minister Antonio Tajani, one of the party's founders, adding that Forza Italia had always voted with the EPP group over Ukraine in the European Parliament.
(Reporting by Alessia Pe, editing by Gavin Jones)