The rightwing Beata Szydlo accused the liberal Tusk of having "brutally violated" the rule of "political neutrality"
Poland's prime minister on Wednesday stressed her opposition to compatriot Donald Tusk's re-election as EU president on the eve of a European summit overshadowed by the row.
The rightwing Beata Szydlo accused the liberal Tusk of having "brutally violated" the rule of "political neutrality" by becoming involved in domestic political disputes.
The attack on Tusk, made in a letter to governments of the 28-member bloc, came a day ahead of a Brussels summit where leaders were expected to rubberstamp a new two-year mandate for the former Polish premier.
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.
"We can't allow a dangerous precedent where the democratically elected government of a member country is politically attacked by the president of the European Council," Szydlo said in the letter, stopping short of citing Tusk by name.
Poland's eurosceptic government on Saturday proposed MEP Jacek Saryusz-Wolski as its official candidate to replace Tusk.
So far Poland has won support only from Hungary -- led by the outspoken, anti-immigration Viktor Orban.
Jaroslaw Kaczynski, the PiS party chief who is widely regarded as Poland's most powerful politician, on Tuesday called arch-rival Tusk "Germany's candidate" for EU president.
Known for his anti-German rhetoric, Kaczynski also said that "Germany is too weak a state to play the role of EU leader."
EU leaders meet Thursday in Brussels for a two-day summit focused on charting a future course for the bloc after Britain leaves.
They are at odds over the contents of a declaration they hope to make on the EU's post-Brexit future at a summit in Rome later this month marking the EU's 60th birthday.
Big guns like Germany and France back a "multi-speed Europe" in which some members could deepen integration faster than others, but Eastern nations like Poland strongly oppose it.
