Italy's maverick Five-Star Movement (M5S) has failed an attempt to reposition itself from Eurosceptic populists to the Europhile establishment.
The party had been allied with Ukip until M5S's founder, Beppe Grillo, proposed parting ways from the British party on Sunday (8 January).
Grillo had planned on turning his back on their coalition in favour of the Liberals in the European Parliament.
Leaving Grillo and the M5S in an embarrassing position, however, the Alliance of Liberals and Democrats for Europe (ALDE) declined their partnership, citing deep-rooted incompatibilities, on Monday (9 January).
"There is insufficient common ground to proceed with the request of the Five Star Movement to join the ALDE Group," leader Guy Verhofstadt, a former Belgian prime minister, said in a statement. "There remain fundamental differences on key European issues."
M5S was formed in 2009 and has grown to become Italy's main opposition party.
It has occupied 17 seats in the European Parliament since the 2014 election, and with Ukip it formed the so-called Europe of Freedom and Direct Democracy (EFDD) party.
When Grillo turned his back on that coalition, former Ukip leader Nigel Farage accused him of trying to join the establishment.
Adding insult to injury as the coalition with Verhofstaft's party failed, political opponents ridiculed M5S for its "incompetence", given that Verhofstadt is a keen federalist with pro-EU views.
"If, until yesterday, Five Star screamed against the euro and Europe, how could they join up with a group that has always taken the diametrically opposite position?" Michele Bordo, a lawmaker from the ruling Democratic Party (PD) said to Reuters. "The only problem here is the consistency of the Five Star Movement."
M5S said it would try to put together a new group called the Direct Democracy Movement in time for the next parliament in 2019, but it gave no indication of who its members will look to ally with next.