Poland's political battle over the judiciary has reached a new flashpoint after President Karol Nawrocki forced his way into the Constitutional Tribunal amid clashes between riot police and anti-government protesters.

Nawrocki and supporters are demanding the reinstatement of top judge Bogdan Swieczkowski, whose removal is backed by Prime Minister Donald Tusk's pro-EUgovernment. Tusk says the move is needed to restore the rule of law, while the opposition calls it an attack on the constitutional order. The long-running dispute has deepened a deadlock that has paralysed Poland's highest court for years.