The Liberals in the European Parliament have rejected a request by Italy's anti-establishment 5-Star Movement to join their group, saying there were fundamental differences in their visions for the future of Europe.

The decision by the Alliance of Liberals and Democrats for Europe (ALDE) is a humiliation for 5-Star, whose members voted earlier in the day to break its alliance with the anti-EU UK Independence Party (UKIP) in favour of ALDE.

"There is insufficient common ground to proceed with the request of the Five Star Movement to join the ALDE Group," ALDE's leader Guy Verhofstadt, a former Belgian prime minister, said in a statement. "There remain fundamental differences on key European issues."

READ: Italy's 5-Star breaks ties with UKIP in European Parliament

Verhofstadt is a keen European federalist whose strongly pro-EU views 5-Star has previously ridiculed.

Some 78 per cent of 5-Star's members who participated in an online vote on Monday backed the proposal by the party's founder Beppe Grillo to abandon UKIP and hook up with ALDE.

The move prompted an angry reaction from UKIP founder Nigel Farage, who said Grillo had "joined the establishment".

5-Star now finds itself in the uncomfortable position of having abandoned its former partners and been rejected by those it had chosen as its new ones.

NO NATURAL HOME

Verhofstadt had paved the way for the entry of 5-Star into ALDE but could not convince a majority of the group's 68 members.

In a short post on Grillo's blog, its main mouthpiece, 5-Star said "the establishment" had blocked its entry into the third largest group in the European Parliament.

Beppe Grillo (pictured) said that the Greens had also rebuffed an offer to team up. Photo: Shutterstock

It said it would try to put together a completely new group called the Direct Democracy Movement in time for the next parliament in 2019, but gave no indication of where its members would go now.

5-Star, Italy's main opposition party, rejects traditional left-right ideological labels and so has no natural home among the main political families in the European Parliament.

Its policies include holding a referendum on membership of the eurozone, universal income support for the poor, tax cuts for small businesses, and clean energy. It attacks the Brussels establishment but does not want Italy to leave the EU.

Grillo said yesterday he had also approached the Greens about a possible alliance, but had been rebuffed.

If ALDE had accepted 5-Star, the Italian group would have been seen as entering mainstream politics and moving away from the anti-establishment fringes, perhaps reassuring other EU capitals that have grown uneasy about its rising popularity.