MADRID (AP) — Spain's lawmakers debated Saturday whether to approve interim Prime Minister Pedro Sánchez's proposal to form a left-wing coalition government for the eurozone's fourth-largest economy.

Sánchez’s Socialist Party wants to form a coalition with the far-left, anti-austerity United We Can party for his next government but needs support from several smaller parties to gain the required parliamentary approval.

It would be Spain's first coalition government since the country returned to democracy in 1978, three years after the death of long-time dictator Francisco Franco.

His proposal is not expected to clinch an absolute majority of 176 votes during a first round of voting set for Sunday. Spain's three right-wing parties have already said their lawmakers would vote against it.

But the Socialists insist they have the votes needed to get the required simple majority — more votes for than against — in a second vote Tuesday to put Sánchez back in the Moncloa Palace, Spain's seat of government.

The Socialists have to rely on the goodwill of some 20 lawmakers who agreed to abstain. Those include the 13-deputy regional Catalan ERC party, one of the groups that want independence for Spain's Catalonia region.

ERC’s support may be in doubt after Spain’s National Electoral Board ruled Friday that the party's imprisoned leader was ineligible to take a European Parliament seat he won in a European Union election in May.

ERC leader and former Catalan vice president Oriol Junqueras was found guilty by Spain's Supreme Court in October of sedition and misuse of public funds for his role in an illegal secession attempt by Catalonia's regional leaders in 2017.

Sánchez and United We Can leader Pablo Iglesias will now be waiting to see if the party changes its position on abstaining from the votes.

Sánchez started Saturday's debate with a long speech in which he laid out the priorities of his proposed government, focusing on a strong defense of public education, health and social services.

But he also mentioned his recent agreement to open talks with ERC on finding a solution to the question of Catalonia's secession, the gravest institutional problem Spain has faced in decades.

“We have to get back to politics and get this conflict out of the courts,” Sánchez told lawmakers in the parliament's 350-seat lower house. “The law by itself is not enough. The law is the basic condition we must respect, but dialogue is the way forward.”

Right-wing parties have accused Sánchez of putting Spain's territorial integrity at risk by agreeing to talk with separatists in wealthy Catalonia, where polls show that roughly half of the 7.5 million residents would support secession.

S ánchez became prime minister in 2018 after leading a push to oust Mariano Rajoy's conservative government. Hekept a minority government afloat until he failed to get a national budget passed early last year and called a snap election.

The Socialists received the most support of any party in the April vote but failed to strike a deal with United We Can. Sánchez was forced to call a second election for November that barely changed the distribution of power in parliament.

Wilson reported from Barcelona, Spain.