Turnout was at its highest since 2008 and particularly high in Madrid and Catalonia
The Socialist party has won Spain’s third general election in four years, but may struggle to form a government, a post-vote survey suggests.
The governing party is set for 28.1%, well ahead of its rivals, while the conservative Popular Party is heading for its worst ever result, on 17.8%.
According to BBC, for the first time since military rule ended in the 1970s, a far-right party is set to win seats in parliament.
Vox, which opposes multiculturalism, feminism, and unrestricted migration, is predicted to take 12.1% of the vote.
The Socialist Prime Minister, Pedro Sánchez, has presented himself as a bulwark against the far right’s advance.
The telephone survey, revealed as polls closed, was carried out instead of an exit poll. Exit polls have been inaccurate in the past.
RTVE predicted the Socialists would win between 116 and 121 seats while its former coalition partner Podemos was heading for 42-45 seats out of the 350 in parliament.
The highly polarised campaign was dominated by issues including national identity, gender equality and the future of Catalonia.
The semi-autonomous region held an independence referendum in October 2017 and declared its independence from Spain weeks later.
A dozen of its leaders have since gone on trial in Madrid, facing charges including rebellion and sedition.
Analysts say support for Vox has been boosted by widespread anger at the independence drive. The party fervently opposes any concessions to the secessionists.
Far-right party Vox candidate Santiago Abascal talks to the media after casting his vote
Women’s rights have also been a key campaigning topic. Gender-based violence has provoked debate and street protests across Spain for years and more politicians than ever are courting women’s votes.
Vox, however, has spoken out against what it calls “radical feminism” that it claims “criminalizes” men.
Speaking after casting his vote at a polling station near Madrid, Prime Minister Sánchez said he hoped for stability.
“After many years of instability and uncertainty, it’s important that today we send a clear, defined message about the Spain we want. And from there a broad parliamentary majority must be built that can support a stable government,” he told reporters.