EU flags Photo: VCG

Tens of thousands of Poles rallied on Sunday in defense of their country's EU membership, after Poland's top court last week issued a landmark ruling against the primacy of EU law.

The demonstrations were called by former EU chief Donald Tusk, now leader of the country's main opposition grouping, Civic Platform, who has warned of the prospect of a "Polexit."

"Tens of thousands of people in Warsaw and in over 100 cities and towns across Poland have come to protest what this government is doing to our homeland," Tusk told a massive crowd in the capital awash with the EU's flags.

Tusk asked people to "defend a European Poland" after a wave of criticism against the ruling both at home and from around the EU.

Membership of the bloc remains very popular according to opinion polls, but relations between Warsaw and Brussels have become strained since the populist Law and Justice (PiS) party came to power in 2015.

The main bone of contention is a wide-ranging reform of the judiciary wanted by PiS, which the EU fears will undermine judicial independence and roll back democratic freedoms.

The latest twist in the long-running dispute was the ruling on Thursday from Poland's Constitutional Court, a body which government opponents say is stacked with PiS allies and therefore illegitimate.

The ruling challenged the primacy of EU law over Polish law in all cases by declaring key articles in the EU treaties "incompatible" with the Polish constitution.

The court also warned EU institutions not to "act beyond the scope of their competences" by interfering with Poland's judicial reforms.

Protesters lit up a central square with their mobile phones, sang the national anthem and chanted "We're staying!"

AFP