His fortunes have since waned even as Italians have ushered in their most right-wing government since World War Two, his popularity eclipsed by the ascent to power of his ally Giorgia Meloni and her nationalist Brothers of Italy party.

Salvini's League, a junior partner in the rightist coalition, is polling below 9% ahead of new European parliament elections in June, while Meloni's party hovers close to the 30% mark, cementing its position as the largest force in Italy.

In an effort to rekindle support, Salvini has driven even further to the right on issues such as crime and relations with Brussels, but the shift has not yet moved the polls his way.

One of the League's European lawmakers, Gianantonio Da Re, told Reuters that Salvini would face internal pressure to step down as leader unless he stopped the rot in the June election.

"We got 34% five years ago. If we get 8% this time, someone will have to answer for it," he said.

League Senator Gian Marco Centinaio - a senior Salvini ally - ruled out the prospect of a looming leadership showdown, or the likelihood of the party performing badly in the EU election: "This possibility doesn't exist," he said.

But the pressure is building.

Salvini's rightward lurch has caused discontent within his own party ranks and poses a problem for Meloni as she seeks to present her government as a reliable partner in Europe and beyond, according to some politicians, pollsters and academics.

The future of right-wing politics across Europe is also in focus, the experts said, with Salvini the flagbearer for a more radical, anti-EU front while Meloni leads efforts to bridge the divide between mainstream conservatives and hardliners.

"Salvini is clearly looking to radicalise his position to be constantly in the news and put Meloni in a tight spot, because she has to maintain a more establishment position," said Mattia Diletti, a politics professor at Rome's Sapienza University.

"But it is a dangerous game. How much does he want to destabilise the government or his own party?"

ELECTORAL DILEMMA

Belying his role as deputy prime minister, Salvini has appeared more like an opposition politician in recent weeks, enthusiastically endorsing protests by Italian farmers, despite the fact that one of their grievances is a government decision to remove agricultural tax breaks.

"The major part of their demands are against the mad, pseudo-green policies of Europe," Salvini said on Jan. 31, without addressing the Italian aspect of their protest.

He has taken particular aim at EU Commission President Ursula von der Leyen, a moderate centre-right politician who has forged unexpectedly close ties with Meloni.

"I wouldn't vote for Ursula von der Leyen," Salvini said last month, just after she had visited Rome to endorse publicly an African cooperation pact that is a cornerstone of Meloni's foreign policy.

In 2019, Meloni's Brothers of Italy won 6.4% of the vote in the European election. Public support for the party has since shot up and is currently polling at about 28%, with the right-wing electorate seeing Meloni as a more trustworthy leader than the mercurial Salvini.

The premier now faces a dilemma.

She is still enjoying a prolonged public honeymoon after her 2022 domestic win, and she could now look to push above 30% in the June election by standing as a candidate herself, and win more seats both for her party and her alliance in Brussels.

Meloni's group is part of an bloc of highly conservative parties in the EU parliament, while Salvini's League is affiliated to the far-right Alternative for Germany (AfD) and Marine Le Pen's Rassemblement National group in France.

"A possible candidacy by Giorgia Meloni would be an important driving force for the Brothers of Italy," Carlo Fidanza, head of the party's delegation at the European Parliament told Reuters, adding that she would decide based on what was best for the government.

Yet a senior party official close to Meloni, who declined to be named, said the prime minister might not stand as a candidate because she feared that if the League suffered a heavy defeat, it would be thrown into tumult and destabilise the coalition.

Under Italian law, government members or lawmakers are not allowed to hold a seat at the EU Parliament, which means Meloni would only stand as a candidate to give her party a boost.

ELECTORAL PRIORITIES

Many Italian voters do not want the government to prioritise hot right-wing issues of the past such as immigration and relations with Europe, according to a poll of 2,000 people published on Jan. 22 by research institute Demopolis which found the top issues were the cost of living, healthcare and taxation.

Pollster Antonio Noto said Salvini's lurch right risked falling flat, with his approval ratings seeing no uptick even as he revives old populist themes that worked well in the past, such as demanding chemical castration for rapists.

"Salvini is conducting the same electoral campaign as in 2019, which was a success back then, but times have changed," Noto said. "Security is important, but healthcare is much more important, and he talks about the former."

There are already murmurings of discontent within the League over Salvini's strategy, notably when he revealed last month that he might put forward as the party's lead candidate an army general who has published a best-selling book in which he disparaged LGBT people, migrants, minorities and feminists.

In a rare sign of public dissent within the League, Da Re - the League's European lawmaker - has announced he will not stand for re-election if General Roberto Vannacci is parachuted into the party line-up.

"That man has nothing to do with our values," Da Re told Reuters. "Salvini thinks that because 200,000 people bought his book, they will then vote for him. But that is nonsense. It will lose us support because many of our supporters oppose this."

While Salvini has dragged the party to the right since taking charge in 2013 and broadened its appeal well beyond its northern strongholds, old stalwarts still hold great sway in the traditional party fiefdoms.

One such grandee is the popular head of the Veneto region, Luca Zaia. He has denied wanting to replace Salvini at the top, saying his focus is Veneto. However, his mandate expires next year and under current rules he cannot seek re-election.

Politics professor Diletti said the moderate Zaia could sweep Salvini away if he ever decided to challenge him.

"Zaia would be a very strong competitor, not just for Salvini but also for Meloni," he added. "That is another reason why she wouldn't want to see the League do badly in June."