The Spanish Socialist Party (PSOE) leader Pedro Sanchez said he would form a "pro-European" government in the wake of his party's victory in the Spanish general election held on Sunday.

Pedro Sanchez, Spain's prime minister, speaks to supporters at the Partido Socialista Obrero Espanol (PSOE) party headquarters in Madrid, Spain, on Sunday, April 28, 2019. (Photo: VCG)

According to data published by the Spanish Interior Ministry with over 99 percent of the votes counted, the PSOE won 28.70 percent of the votes to win 123 seats in the 350 seat Spanish Congress of Deputies.

This means the PSOE had 37 more seats than in the June 2016 election when the Socialists won 22.63 percent of the vote and 85 seats.

Sunday saw the Socialists win 57 more seats than the right wing People's Party (PP), who ranked second in the election, but saw their vote share plunge from 33.01 percent in June 2016 to 16.69 percent on Sunday as support for right wing parties was split into three.

The PP lost votes to Albert Rivera's center-right party Ciudadanos, which gained 15.85 percent of the votes and won 57 seats, while the extreme right wing Vox claimed 10.26 percent of the votes to enter Congress for the first time with 24 seats.

"The Socialist party has won the election and with that, we have won the future and left the past behind," said Sanchez from his party's headquarters in Madrid.

"We have shown this is a great and solid democracy, where millions of people have voted to defend democracy and the future," he said.

Sanchez said that the victory of the left against the right-wing block showed that Spaniards "don't want to go backwards, but want a country that looks to the future."

"We have also sent a message to the Spanish people, Europe and the world that you can win against reactionaries and authoritarianism," he added.

Although he will now need to form a coalition government, Sanchez was clear the election was "a question of winning and governing," and that "we have won the election and we are going to govern Spain."

Thousands of Socialist supporters chanted "with Rivera no!" in the street outside the PSOE headquarters on two occasions, making it clear they do not want to see a coalition with Ciudadanos.

Although Sanchez said he had "heard" the chants, he insisted he and his party would be "the prime minister and the government of all Spaniards," and would extend their hands to "all constitutionalist parties."