Leader of the 5Star Movement Beppe Grillo | Marco Bertorello/AFP via Getty Images | Marco Bertorello/AFP via Getty Images MEPs from Italy’s 5Star may switch to Liberal group M5S’ Grillo consults members on changing allegiances, prompting Socialist criticism of Liberal leader Verhofstadt.

Italy's 5Star Movement is in talks for its 17 MEPs to switch group and join the Alliance of Liberals and Democrats for Europe (ALDE) in the European Parliament, according to its leader Beppe Grillo, who asked party members Sunday to vote on the option.

The move would take M5S out of Europe of Freedom and Direct Democracy (EFDD), the group it co-founded in 2014 together with Nigel Farage's UKIP and a smattering of MEPs from other countries.

It would also exacerbate tensions between ALDE and rival groups. Liberal leader Guy Verhofstadt is running for president of the European Parliament against the Socialists' Gianni Pittella and conservative Antonio Tajani, both Italians whose parties are bitter enemies of M5S.

An alliance between ALDE and the M5S, which wants to hold a referendum on Italy's membership of the euro, would be surprising given that most of the Liberal group's 68 MEPs are avowedly pro-European, like Verhostadt.

Didrik de Schaetzen, a spokesperson for ALDE, said there would be no comment from the group "before the M5S consultation is over."

The talks were revealed by Grillo in his blog, where he also said an approach to the Greens in the Parliament had been rejected.

"UKIP has achieved its political goal," wrote Grillo, in reference to the U.K. vote to leave the European Union. As a result, "remaining in the EFDD means spending the next two and a half years with no shared political objective, within a delegation that is not interested in producing concrete results."

He also expressed displeasure at allegations that some EFDD members had misused group funds.

But "refusing to belong to any political grouping means joining the independents and losing out on opportunities" to speak, draft reports and obtain funding. Together, the Liberals and M5S would be the third largest in the European Parliament, said Grillo.

M5S' conditions for joining include not being bound by group whips and a joint commitment to greater citizen participation in the "political life" of the EU institutions. Grillo said the two sides would commit to promote policies "such as the simplification of the Brussels bureaucracy, resolving the immigration emergency via a system of permanent relocation, the promotion of the green economy and the development of the digital economy together with more job opportunities."

He gave voters the choice between joining the Liberals, becoming independents or remaining in the EFDD.

Patrizia Toia, an Italian Socialist MEP, said it was "not an edifying sight" to see Grillo courting first the Euroskeptics and then the federalists, while Verhofstadt was engaging in the "sort of incoherent backroom deal is exactly what alienates citizens from the European project," she said.

The departure of the M5S would leave the EFDD intact, but only just. Parliament rules stipulate that groups must have 25 MEPs from at least seven EU countries. Without Grillo's party, the EFDD would have 27 MEPs, including 20 from UKIP, from the required number of EU countries.

This article has been updated to correct Italian MEPs' names.