If Puigdemont fails to answer Thursday’s High Court summons, an arrest warrant could be issued that would make it virtually impossible for him to stand in a snap regional election called by the Spanish government for Dec. 21.

Prime Minister Mariano Rajoy sacked Puigdemont and his government on Friday, hours after the Catalan parliament made a unilateral declaration of independence in a vote boycotted by the opposition and declared illegal by Spanish courts.

Puigdemont travelled to Belgium at the weekend with other members of the dismissed Catalan administration and hired a lawyer.

“Those summonses are part of proceedings that lack any legal basis and only seek to punish ideas. This is a political trial,” Puigdemont said in a statement signed by “the legitimate government of Catalonia”.

The High Court summoned Puigdemont and 13 other former members of the Catalan government to testify in Madrid on Thursday and Friday on the prosecutor’s charges.

A judge will then decide whether those called to testify should go to jail pending an investigation that could take several years and potentially lead to a trial. The judge might also grant them conditional bail or order them to surrender their passports.

If Puigdemont and his associates did not turn up, the judge would be more likely to order them jailed as a flight risk.

The courts have also told the Catalan secessionist leaders to deposit 6.2 million euros (5.44 million pounds) by Friday to cover potential liabilities.

Three former Catalan government advisors returned to Spain from Belgium late on Tuesday and were greeted at Barcelona’s international airport by a small crowd chanting “off to prison”.

Puigdemont said on Tuesday he would only go back to Spain when given unspecified “guarantees” by the Spanish government. He said he accepted the election called by Rajoy for December and Madrid said he was welcome to stand, though the legal proceedings might prevent that.

Uncertainty over how the crisis will play out has prompted more than 1,800 Catalonia-based companies to move their legal headquarters out of the region and the government to lower its national economic forecasts for next year.

On Wednesday, rating agency Moody’s said the declaration of independence and the suspension of self rule were credit negative for the region and the country, and that associated uncertainty would damage sentiment and consumer spending.

Moody’s raised Spain’s credit rating to Baa2 in 2014 as the country emerged from a prolonged economic slump.

On Tuesday, Moody’s affirmed Catalonia’s long-term issuer and debt ratings of Ba3, saying the government’s reinforced control compensated for the increased risks, in particular the region’s rapidly deteriorating business climate.