Italy's Five Star Movement (M5S) wants to team up with like-minded anti-establishment parties and form a new grouping within the European Parliament to wrest power from the traditional left and right, its leader said Sunday.

"I don't think that the traditional parties have the potential to attain an absolute majority in the European Parliament," M5S chief Luigi di Maio said.

Speaking at an event in Warsaw with Poland's populist Kukiz'15 movement and Croatia's Zivi Zid (Human Shield) party, Di Maio said the traditional differentiation between politics of the "left" and "right" was "outdated".

"I prefer to distinguish between good and bad ideas," said Di Maio, who is Italy's deputy prime minister.

He said his party was open to collaboration with any political movement "that comes up with good proposals."

Di Maio's Polish host, the punk-rocker-turned-politician Pawel Kukiz, said his party's slogan for the EU elections would be "Poland in Europe, Europe for Poland" and that the focus of his campaign would be the fight against the "ossified elites".

"We cannot accept that Europe is in the hands of the European Commission, which in reality serves the interests of two states, a sort of marriage between (French President Emmanuel) Macron and (German Chancellor) Angela Merkel," he said.

Analysts have said that Italy's populist government - comprised of Di Maio's M5S and the far-right League - is on its last legs, with the two parties bitterly at war since taking power last June.