Deep-rooted hostility built up over years must be overcome if the anti-establishment 5-Star Movement and the center-left Democratic Party (PD) are to strike a deal to form a government and end Italy’s post-election stalemate.

The third-largest economy in the eurozone has been in political limbo since a vote on March 4 produced a hung parliament. A center-right alliance led by the anti-immigrant League won the most seats and 5-Star emerged as the biggest single party. The PD came a distant third.

After an initial attempt to form a coalition between the center-right and 5-Star ended in failure, President Sergio Mattarella last week asked 5-Star and the PD to try.

If it were only about policies, the sides should be able to find some common ground, especially since 5-Star’s 31-year-old leader Luigi Di Maio has recently shifted his party towards more moderate positions, close to those of the PD, in terms of fiscal policy and Europe.

Both parties want to try to renegotiate Europe’s fiscal rules to allow Italy to cut taxes and increase investment, but say they would hold the budget deficit below the EU’s ceiling of 3 percent of gross domestic product.

5-Star has abandoned a previous pledge to hold a referendum on Italy’s euro membership and its flagship policy, a universal income support for the poor, is essentially a more generous version of a policy already adopted this year by the PD.

Three policy priorities put forward this month by PD leader Maurizio Martina, centered on increasing welfare provisions and fighting poverty, were broadly similar to recipes advocated by 5-Star.

However, the PD is split between factions that want to go into opposition, led by its former leader and Prime Minister Matteo Renzi, and others that want to negotiate with its most bitter adversary during the last five years of PD government.

Renzi’s successor, acting leader Martina, is in the second group, and he has called a meeting of the PD’s executive body on Thursday to decide whether to begin talks.

The 5-Star’s leader Di Maio wants the two sides to come to terms on a limited number of policy goals, but Renzi loyalists do not even want to discuss policies.

“It’s a waste of time, it can only end in failure,” said PD president Matteo Orfini. “We are incompatible with 5-Star in terms of political culture, programs, history and what has happened in these past years.”

Renzi’s supporters say that as a junior partner to 5-Star the PD would get no credit for any government successes and would share the blame if things go wrong. Advocates of a deal say the greatest danger for the PD would be a quick return to the polls, where it risks losing even more support.