Additionally, the Spanish Supreme Court is set to decide the fate of 10 other leaders who were jailed pending a probe into their role in the Catalan independence drive. It had ERC, Puigdemont's Junts per Catalunya (Together for Catalonia) and the far-left anti-establishment CUP party winning 66 or 67 of the parliament's 135 seats. It said 3,000 people were quizzed via telephone calls from November 23 to 27.
Spanish Prime Minister Mariano Rajoy and fellow opponents of Catalan independence, meanwhile, have hitched their hopes on a record turnout on December 21 to return a legislature in favour of unity with Spain.
Axed Catalan separatist leader Carles Puigdemont arrived on Monday for an extradition hearing in Belgium as Spain seeks to have him sent back to face sedition charges over his region's independence drive.
The lawyers of Puigdemont and the four former Catalan ministers argued that the facts are not punishable in Belgium and that in case of extradition to Spain there is a risk of infringement of their clients' fundamental rights.
The judge considers that it remains to be seen if their pledges to abide by Spanish law and renounce unilateral independence for Catalonia is "truthful and real", according to a statement by the Supreme Court.
"Whatever happens, they will be in Brussels until the 21st of December, and I believe it will be until mid-January in theory", Jaume Alonso Cuevillas told Catalonia Rac1 radio station.
Magistrate Pablo Llarena ordered ousted Catalan Vice President Oriol Junqueras, the former regional interior minister Joaquim Forn and the leaders of two Catalan separatist groups to remain in jail without bail.More news: Officials Think Body of Missing North Carolina Girl Mariah Woods Found
Spain wants to judge the five Catalan former leaders among others for "rebellion" (a crime punishable by 25 to 30 years in prison) and "sedition", for having successfully started a secessionist process.
Madrid called the new elections after the independence declaration, while dismissing Catalonia's government and suspending the region's autonomy.
Madrid hopes the elections will restore normality to the wealthy northeastern region, which declared independence in vain following the referendum.
His lawyer said at the weekend that Puigdemont would remain in Belgium until after the Catalan elections.
The Dec. 21 ballot is shaping up as a plebiscite between those for and against independence.
Prosecutors last month asked the judge to approve the European arrest warrant issued by Madrid for the five in the opening round of what could become a protracted courtroom battle. Election campaigning is due to begin at midnight local time.
Whatever decision is made on Monday, two appeals will be possible and a final ruling could well only come only after the vote.