Italy's anti-establishment Five Star Movement (M5S) will vote Thursday on whether to ditch leader Luigi Di Maio after the party's flop at European elections, the deputy prime minister said.

The M5S rules in coalition with Matteo Salvini's far-right League, which won a resounding victory in Italy on the back of an "Italians First" campaign, dealing a blow to the Movement and threatening the stability of the government.

"You decide. I am asking to put my role as party leader to the vote," Di Maio said on the M5S blog Wednesday.

"If the Movement renews its faith in me, we'll get to work... with even more commitment and dedication," he added.

The vote on whether he should stay on will take place on the M5S online platform on Thursday.

The EU vote results confirmed the reversal of fortunes of the ruling parties, with M5S -- which pocketed 32.5 per cent at the general election -- taking home just 17 per cent on Sunday compared to the League's 34 per cent.

"I had promised to get the Movement into government... and we did. I never gave any less than 100 per cent," Di Maio said.

"I would never have thought working hard would be a fault," he added, in an apparent reference to Salvini, who famously spent fewer than 20 days in his office between the start of the year and the vote as he toured the country campaigning.

Di Maio has blamed the M5S's poor performance on low voter turnout, as well as a mud-slinging campaign by the League against which it was slow to retaliate.