Sanchez sworn in as new prime minister by Spain's King Felipe VI

Socialist party leader Pedro Sanchez was sworn in as prime minister on Saturday by Spain's King Felipe VI.

The 46-year-old took the oath of office in the morning hours at the Palace of Zarzuela on the outskirts of Madrid.

Sanchez, the seventh prime minister of Spain since the end of the Franco dictatorship in 1975, is the first premier to come to power without a national vote for parliament.

Instead, Sanchez ascended to Spain's top political post after putting up a no-confidence motion against former prime minister Mariano Rajoy, who lost the vote Friday.

The vote was triggered by a scandal involving Rajoy's centre-right People's Party (PP), which saw former PP members handed jail sentences this month for their part in the long-running Operacion Guertel corruption case.

The no-confidence vote was supported not only by Sanchez's PSOE party, but the leftist alliance Unidos Podemos and several regional parties.

While Sanchez hasn't yet announced his new cabinet, it is expected that Unidos Podemos will receive several ministries.

It's not clear, however, to what extent Sanchez had to make promises in advance to the smaller regional parties and if they would receive cabinet posts.