ROME (REUTERS) - Italian Prime Minister Giuseppe Conte threatened to quit on Monday (June 3), telling the ruling coalition's two feuding parties either to put an end to their brawling or take the country back to elections.

Conte, a technocrat leader with no political support base, called a news conference to make the extraordinary ultimatum after months of bickering inside his year-old coalition of right-wing populists and anti-establishment lawmakers.

"I'm not here just to scrape by, or drift," Conte told a packed news conference at the prime minister's residence.

"If they do not clearly assume their responsibilities as I have requested ... then I will resign."

The League and 5-Star Movement have been battling over everything from major infrastructure projects and immigration to the historical significance of national holidays and who is to blame for a cruise-ship accident in Venice at the weekend.

The feud intensified following European parliamentary elections last month when the League won 34 per cent of the vote, leap-frogging above 5-Star and fuelling speculation that League leader Matteo Salvini could ditch his coalition partners.

Conte told reporters his government faced a complex 2020 budget process later this year and that the country needed the confidence of financial markets.

During the recent government in-fighting, investors sold off Italian bonds, raising concerns over Rome's ability to manage its enormous public debts of around 2.3 trillion euros (S$3.53 trillion).

"We must not let sterile controversies and pointless arguments waste our precious energy or distract from government objectives," Conte said.

Italy faces the possibility of European Union disciplinary procedures this week for a breach of EU fiscal rules, which Salvini says are outdated and harmful to Italy's economy.

Conte said the government should respect EU budget rules until such time as they are changed.