ROME (Reuters) - The far-right League emerged as Italy's largest party in Sunday's European parliamentary election, overtaking its coalition partner the 5-Star Movement, which lost a third of its voters in a year, exit polls said.
If confirmed, such a result could alter the balance of power within the bickering government, giving greater authority to League leader Matteo Salvini, who is pushing for swingeing tax cuts in possible defiance of EU budget rules.
Four exit polls predicted the League took anywhere between 26.0-31.0 percent of the EU vote, up from some 17 percent at the 2018 national election and 6.2 percent at the last EU ballot in 2014, boosted by its strong anti-immigrant message.
However, the League had been polling as high as 37 percent earlier this year, suggesting its momentum had ground to a halt following months of surging popularity.
The 5-Star, led by another deputy prime minister, Luigi Di Maio, took between 18.5-23.0 percent, according to the various polls, compared with 32 percent last year and 21.1 percent five years ago.
The same polls suggested 5-Star had been overtaken on Sunday by the opposition, pro-Europe Democratic Party (PD), which was seen winning between 20.5-25.0 percent from 18.7 percent in 2018 and 40.8 percent in 2014.
Relations between the League and 5-Star have deteriorated during the election campaign and there has been speculation that the coalition could collapse following the vote because of big differences over issues such as taxes and regional autonomy.
Salvini has said repeatedly the election would have no bearing on the make-up of the government and has denied suggestions he would demand more ministerial positions for his party in the event of victory.
However, he has also said he expected 5-Star leaders to drop their resistance to projects close to his party.
These include his drive to introduce a flat tax in the 2020 budget, regardless of fears this would push the deficit beyond EU limits. He also wants swift approval for more autonomy for the regions and has called on 5-Star to drop objections to major infrastructure programmes, including a trans-Alpine rail link.
5-Star has traditionally fared better at general elections, when turnout is much higher. But a loss to the PD would nonetheless represent a blow to Di Maio and mean he could face pressure from party faithful not to make any major concessions to Salvini, which might further erode grass-root support.
The exit polls forecast that former prime minister Silvio Berlusconi's Forza Italia party had won between 8-12 percent on Sunday, while the nationalist Brothers of Italy party was seen taking between 4-7 percent.
(Reporting by Angelo Amante; Editing by Crispian Balmer)