PRO-independence parties in Catalonia have for the first time triumphed in a Spanish general election.

Their success will limit the options open to Socialist party (PSOE) leader Pedro Sánchez, whose refusal to even discuss self-determination led to Sunday’s snap poll.

READ MORE: Greg Russell: In Catalonia, Sanchez is caught between a rock and a hard place

The Republican Left (ERC, or Esquerra) is now the first party in Catalonia, which has not happened since 1936.

Along with Together for Catalonia (JxCat) they have 22 seats, a rise of six on the 2016 election.

ERC’s Oriol Junqueras, one of the highest-profile candidates who are imprisoned and on trial over the 2017 independence referendum, was elected to Congress and his party and prison colleague, Raül Romeva, topped the list for Barcelona’s seat on the Spanish senate with more than 900,000 votes.

JxCat candidates who are on trial – Jordi Sànchez, Jordi Turull and Josep Rull – also won Congress seats, after taking part in only a handful of news conferences by video from inside Soto del Real prison in Madrid.

PSOE gained 37 more seats in the Spanish Parliament taking its total to 123, but it still fell short of the 176 majority needed to form a government.

Sánchez’s deputy in the Spanish government, Carmen Calvo, said yesterday that PSOE would continue to rule alone. She said: “We think we can continue with this formula that we have already started.

“We will try ... above all because we believe ... that in a very short space of time people have understood us very well.”

Sánchez had initially indicated that he would “soon” open talks with other parties.

But his options are limited after he was involved in bitter election debates with Pablo Casado, leader of the right-wing PP – whose vote collapsed – and the Citizens party leader Albert Rivera.

Neither is he likely to want to partner with the far-right Vox, who gained a tenth of the vote and 24 seats.

His preference would be for a left-wing alliance, which restricts his options even further.

The left-wing, anti-austerity Unidas Podemos (United We Can), is led by Pablo Iglesias, who has already offered Sánchez his support.

However, it supports a referendum on self-determination and has called for the release of the political prisoners.

Even if Sánchez could find a way of working with Podemos, its 42 seats would still deny him a working majority. His only option then would be to seek support from pro-indy parties in Catalonia and their Basque Country colleagues – the pro-indy EH Bildu has doubled its number of seats from two to four.

Meanwhile, Spain’s Central Electoral Board (JEC), has stopped exiled former Catalan president Carles Puigdemont, ex-education minister Clara Ponsati and Toni Comin, who was health minister, from standing in the European elections next month. It said they were ineligible because they were not registered as Spanish citizens living abroad.

The trio said the ruling was a “flagrant violation” of their rights and “proof of collusion between the judiciary, which should be independent, and certain political interests”.