MADRID (Reuters) - Eight former Catalan cabinet members currently in custody awaiting trial will appear before the Supreme Court on Friday, after requesting their release ahead of a regional election Dec. 21 in the wake of a disputed independence referendum. Sacked regional vice-president Oriol Junqueras, one of his ERC party s main candidates for the election, has asked to be allowed to leave jail in order to campaign in the vote which was called by Madrid. Junqueras and seven other former members of the Catalonia regional cabinet were jailed on Nov. 2 pending trial on charges of sedition, rebellion and misappropriation of funds after the Catalan government declared independence from Spain. The Oct. 1 referendum, declared unconstitutional by Spain, and the subsequent proclamation of independence by the wealthy northeastern region pushed Spain into its worst political crisis in decades and led Madrid to impose direct rule on Barcelona. The eight jailed cabinet members, whose original hearing was at the Spanish High Court, had their case moved to the Supreme Court after the presiding judge argued the different Catalan cases should be tried in the same court.   Earlier November, the Supreme Court released Catalan parliament speaker Carme Forcadell on bail of 150,000 euros after she agreed to renounce any political activity that went against the Spanish constitution. All the eight former cabinet members have said they would abide by a ruling giving Madrid control over the region, according to their lawyers, although some of them said they did not agree with this unprecedented move stripping power from the rebel administration. Campaigning for the Dec. 21 election, seen by pro-independence parties as a de facto plebiscite on secession from Spain, starts on Monday at midnight.   The former leader of Catalonia, Carles Puigdemont, in self-imposed exile in Belgium and subject to an arrest warrant from Spain for rebellion and misuse of public funds, has called the elections the most important in the region s history. Barely a quarter of Catalans want to continue with the project of creating an independent state, a recent survey by pollsters Metroscopia showed. However, polls show the vote split evenly between parties seeking independence from Spain and those wanting to remain part of a united country. The leaders of Catalan civic groups Asamblea Nacional Catalana (ANC) and Omnium Cultural Jordi Sanchez and Jordi Cuixart - who were imprisoned last month - also testify before the Supreme Court over their role in the independence drive. 