The head of Poland's ruling rightwing party on Tuesday called EU President Donald Tusk, a fellow Pole vying for a second term, "Germany's candidate" whose re-election would sow crisis.
Known for anti-German rhetoric, Jaroslaw Kaczynski also said that "Germany is too weak a state to play the role of EU leader."
"It lacks the adequate economic or military clout" to lead the continent, Kaczynski told the nationalist Gazeta Polska weekly in an interview published by the Polish PAP news agency a day before the magazine hits newsstands on Wednesday.
Kaczynski also insisted that "Germany's current dominance of the EU is an artificial situation resulting from economic relations and the incredible opportunism of elites in Brussels."
The former Polish prime minister also insisted that the arrangement was "doomed to catastrophe, and the election of Tusk to a second term will be yet another move bringing the entire Union closer to an even greater crisis."
Kaczynski's governing populist Law and Justice (PiS) party surprised many at the weekend by suddenly proposing Euro-MP Jacek Saryusz-Wolski instead of Tusk, its long and bitter foe.
Now, a row over Poland's bid to replace Tusk threatens to overshadow a summit this week that was meant to focus on post-Brexit unity.
The two-day summit starting Thursday risks being consumed by splits along old east-west lines as Hungary as signalled support for the rival candidate proposed by the eurosceptic Polish government.
Kaczynski also accused Tusk, whom he sees as his arch-rival in Polish politics, of violating rules on neutrality for EU presidents by allegedly "openly siding" with his former liberal Civic Platform (PO) party.