Hundreds of thousands of protesters have gathered in Warsaw for one of Poland's largest demonstrators since the fall of communism in 1989.

Axar.az reports that most opposition parties have called on supporters to join the march against the nationalist Law and Justice party (PIS), led by Jaroslaw Kaczynski.

Among those attending are former Prime Minister Donald Tusk, and former President Lech Walesa.

The PiS has condemned the gathering as a "march of hate".

The mayor's office for Warsaw has estimated half a million people attended the event, which fell on the 34th anniversary of Poland's first partially-free elections.

Many travelled from across the country to take part, and simultaneous demonstrations have been held in other Polish cities like Krakow.