Spanish Prime Minister Pedro Sanchez’s chances of keeping his job will be tested Thursday when lawmakers vote on his choice as speaker of parliament.

While normally a routine procedure, the ballot this time will be the tightest in four decades of democracy and provide a first indication of whether Sanchez can muster enough backing to remain in power following July’s election stalemate.

Sanchez’s Socialist party on Tuesday said it will propose Francina Armengol, a former regional president of the Balearic Islands, for the position of speaker of the lower house, but it is still unclear whether she will gain enough support in the highly fragmented 350-member chamber.

Two small regional nationalist parties, one Catalan and one Basque, are crucial to pick a winner but are yet to make their intentions clear.

Sanchez and the leader of the main opposition conservatives, Alberto Nunez Feijoo, are both vying to gain support from lawmakers to secure the job of prime minister, which Sanchez is currently performing in a caretaker capacity.

Last month’s inconclusive election handed the country’s left- and right-wing blocs roughly the same amount of support and made a handful of representatives from smaller parties potential kingmakers.

The speaker’s election — which doesn’t typically draw much attention outside core political circles — is expected to offer the first clear hint as to who holds the upper hand.

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Feijoo’s People’s Party and two other parties have a clear chance of combining for 171 votes, while Sanchez is expected to get 172 from a group of allies, including the Basque nationalist PNV. The seven lawmakers of the Catalan separatist group Junts and the one deputy of the Canary Islands’ CC could potentially break the deadlock.

Carles Puigdemont, the leader of Junts, said in a post Wednesday on X, the platform formerly known as Twitter, that he would require strong guarantees because “we have no confidence in Spanish political parties.”

Puigdemont, a former Catalan regional president who has been on the run from Spanish courts since 2017 and living in Belgium, also said that talks on picking the speaker were completely separate from those to choose a premier.

For Feijoo, bringing on the PNV and Junts, both parties with strong pro-business roots, would be a natural move.

However, given the importance of regional nationalism in Spain and Feijoo’s proximity to far-right group Vox, the third-largest party in parliament, it is unlikely to happen. Vox is staunchly anti-separatist.

Both the election of the speaker and the prime minister require an absolute majority in the first round of voting or a simple majority in the second. There isn’t yet a date for the premiership vote.

The speaker is parliament’s presiding officer and Spain’s third-highest elected official. Eight other officials are also named to form the so-called parliamentary bureau — the organ that presides over sessions. It also has powers to delay or fast-track discussion of legislation and the interpretation of parliamentary rules, such as which parties are entitled to having their own caucus.