Vote on minister's immunity puts Italian populists in bind Italy's populist 5-Star Movement is asking its supporters to vote online on whether the leader of its coalition partner should be prosecuted.

ROME -- Should senators from Italy's anti-establishment 5-Star Movement strip the firebrand leader of the far-right League of his immunity from criminal prosecution, possibly jeopardizing the populist government in which the two parties are coalition partners?

The decision has them in a bind.

If they vote no, they risk alienating supporters by betraying a sacred principle of the Movement: politicians deserve no privilege beyond the ones shared by all citizens. If they vote yes, they risk worsening internal tensions already testing the 8-month-old government's viability.

So leaders of the 5-Stars, who bill the party as an internet-based democratic movement, have kicked the verdict down the line. They are asking supporters to vote online Monday on whether to lift or maintain League leader Matteo Salvini's parliamentary immunity as a senator.

Prosecutors in Catania, Sicily, are investigating Salvini, the interior minister in the coalition government, on a possible kidnapping charge over the treatment of 177 migrants in August.

The migrants were rescued by a private aid ship and transferred to an Italian coast guard vessel. Salvini refused for five hot days to let them disembark in Sicily. The anti-migrant minister contends private rescue boats essentially help human traffickers.

The Italian Senate commission on immunity is scheduled to vote on Salvini's immunity Tuesday. Whatever the recommendation, the full Senate would have the final say next month. If charged and convicted, Salvini could face a maximum prison sentence of 14 years.

Movement lawmakers sounded defensive Sunday when asked about how they were opting to put their egalitarian principle on the line - or in this case, online, too.

"This isn't synonymous with weakness" 5-Star Senate whip Stefano Patuanelli said of Monday's polling of supporters. "This is the participatory democracy that all of us of the Movement have always wanted and hoped for."

Meanwhile, Salvini dismissed speculation that he cut a deal with 5-Star leaders: keeping his immunity in place in exchange for Salvini dropping his support for completing a high-speed rail line in northern Italy the Movement has vowed to block.

"We're not at a fish market" haggling, Salvini told reporters.

"I'm convinced I defended the security and borders of our country," he said, adding that as far as the 5-Stars go, "Everyone votes according to conscience."

Both in opinion polls and a recent regional election, the popularity of the 5-Stars dipped while the League gained. If the League finishes strongly in May's European Parliament elections, Salvini could be tempted to pull the plug on the current governing coalition in a bid for an early national election.

Meanwhile, critics of the 5-Stars delighted in the Movement's dilemma.

"The 5-Star Movement can be coherent with the principles for which it was born (and for which it got votes) or fudge it in order to survive (for a few months)," tweeted former Democratic Party Premier Enrico Letta. If the 5-Stars block Salvini's prosecution, "it loses its DNA."

Ultimately, the opposition Forza Italia party of Silvio Berlusconi, who lost his own Senate seat in a previous legislature after being convicted of tax fraud, could come to Salvini's rescue.

While criticizing the online vote strategy, Forza Italia contends prosecutors who target lawmakers are politically motivated. The party's leadership says its senators will oppose removing Salvini's immunity.