MADRID, SPAIN - JANUARY 04: Spain's interim Prime Minister Pedro Sánchez gestures during his speech during the investiture debate at the Spanish Parliament on January 04, 2020 in Madrid, Spain.

Spain is on track to get a new government Tuesday, but its economic and political future remains uncertain.

Socialist leader Pedro Sanchez is set to receive enough support at a parliamentary vote Tuesday that will put an end to almost one year of political uncertainty. Sanchez won a snap election in April of 2019 but struggled to form a government led by his Spanish Socialist Workers' Party (PSOE). As a result, another snap vote took place in November, which is now culminating with the first coalition government that Spain has seen in modern times.

"A progressive coalition" – is how Pedro Sanchez described his deal with Unidas Podemos, a group of left-leaning parties, whose leader Pablo Iglesias became known in the aftermath of the sovereign debt crisis for his opposition to austerity policies. However, Pedro Sanchez will also be relying on other smaller parties to govern the southern European country.

"The new PSOE-Unidas Podemos government will not probably have a stable parliamentary majority to rely on, which means it will have to negotiate most policy measures on a case-by-case basis with other parties," Antonio Barroso, deputy director at the research firm Teneo, said in a note Friday.

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Pedro Sanchez's agreement with Unidas-Podemos received 166 out of 350 votes in the Spanish Parliament on Sunday. The result did not deliver the absolute majority that they needed, but a new vote is scheduled for Tuesday, where a relative majority will be enough to install the new government.

Nonetheless, Florian Hense, economist at Berenberg bank, told CNBC Monday that it is "not very likely" the new government will last until the end of the mandate.

"It is a coalition government, which is not very common in Spain, it lacks an outright majority, and whose likely simple majority relies on the abstention, of among many other regional parties, the big separatist ERC (a Catalan separatist party)," Hense told CNBC via email.