A court Tuesday summoned Catalonia's president to face possible charges over a 2014 ballot on independence from Spain, raising pressure on separatists after they won control of their regional parliament. The move by the Catalonia high court came as a bitter standoff between Artur Mas and the Spanish government deepened after he and his separatist allies declared victory in Sunday's regional election.

Buoyed by that result, the separatists vowed to push on towards a declaration of independence by 2017 but Madrid promised to defend the unity of Spain. In a judicial investigation dating back to last year, the court called Mas to go before a judge on October 15, in a written ruling released on Tuesday. Prosecutors accuse him of civil disobedience, abuse of power and embezzlement of public funds for pressing ahead with last November's ballot. The court also summoned two other members of his former regional administration to appear on October 13. The three are accused of breaking the law by organizing the ballot on November 9, 2014, in defiance of an injunction by Spain's Constitutional Court. If found guilty, they could be banned from public office.

Mas wanted his rich northeastern region to follow the example of Scotland by holding a referendum on independence. The Constitutional Court's ban forced him to water down his plan for an official vote. Instead, the November ballot was merely symbolic and organized by volunteers. But Mas and fellow officials are accused of using public resources to stage the vote, setting up polling stations in schools and electoral information online.

Nearly 2.3 million of Catalonia's 5.5 million voters took part in the symbolic ballot, with about 1.9 million voting for independence, but the poll was not legally binding. Mas then called a snap regional election on September 27 and campaigned in a pro-independence alliance. His group won enough seats in Sunday's vote to control the regional parliament if it teams up with the radical left-wing movement CUP. Both groups said that result gave them a mandate to proceed to a declaration of independence and said they would start this week holding meetings to reach an accord.

Spain's Prime Minister Mariano Rajoy insisted he would not negotiate on demands for independence. Three months ahead of a general election, Rajoy is vowing to preserve unity in Spain, the eurozone's fourth-biggest economy, as it recovers from an economic crisis.

Sunday's result put the wind in the sails of the separatists, but the court summons and the need to strike a deal with the CUP puts Mas in a tight spot. The Together For Yes alliance must negotiate a coalition with the CUP, which refuses to accept Mas as leader of the separatist movement. Mas knew ahead of Sunday's vote that he would likely be summoned to court in the pending case, but the timing of its announcement prompted separatists to brand the lawsuit politically motivated. The summons "is the best proof of why we need to be an independent country," said Oriol Junqueras, leader of the center-left ERC party which joined in Mas's separatist electoral alliance. "While we are part of the Spanish state, issues that would be quite normal in any other country in the world, such as asking citizens their opinion, get turned into lawsuits, charges and court hearings," he said on the radio.

The CUP resents Mas's economic austerity policies in the economic crisis. But one of its leaders, outgoing deputy David Fernandez, expressed support for him in the court case. "Total solidarity against a neurotic, anti-democratic authoritarian and inquisitorial state," Fernandez wrote on Twitter.