Poland accused Germany of forcing its will on the EU on Thursday, in protest at the re-election of the bloc’s President Donald Tusk, a Pole and political rival to whom Warsaw’s rightwing government is staunchly opposed.

Twenty-seven European Union leaders voted at a summit in Brussels to give ex-Polish premier Tusk a new two-and-a-half-year mandate with only Poland voting against.

“We know that this is now a Union under Berlin’s diktat,” Poland’s Foreign Minister Witold Waszczykowski was quoted as saying Thursday by the rightwing wPolityce.pl news website.

“This gives rise to a very dangerous European union. A very toxic union, that could harm many countries,” Waszczykowski warned, adding that Thursday’s vote suggested that a so-called “multi-speed Europe” was taking shape.

EU powerhouses France and Germany on Monday endorsed the idea of a “multi-speed” EU in which some members could deepen their integration faster than others, a move that Poland and other eastern EU countries staunchly oppose.

“We want to know what kind of blackmail or pressure was used to vote against our candidate,” Waszczykowski said, referring to MEP Jacek Saryusz-Wolski whom Warsaw had officially proposed to replace Tusk.

Jaroslaw Kaczynski, the powerful head of Poland’s ruling rightwing Law and Justice (PiS )party, accused political arch-rival Tusk of having “betrayed his own country.”

He also voiced his disappointment with fellow rightwinger Hungarian Prime Minister Viktor Orban for endorsing Tusk.

Poland’s PiS government accuses the liberal Tusk of having “brutally violated” the rule of “political neutrality” by becoming involved in domestic political disputes.

Since winning power in October 2015 elections, Szydlo’s right-wing Law and Justice (PiS) government has pushed through a string of controversial reforms that triggered mass protests at home and an EU threat of sanctions over rule of law violations.

Kaczynski on Tuesday called Tusk “Germany’s candidate”, warning that his re-election would sow crisis in the EU.

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, he added.