MADRID, Dec. 11 (Xinhua) -- Spanish Supreme Court Judge Pablo Llarena asked the Civil Guard on Monday to compile a report about those responsible for organizing the strategy used to attempt to achieve Catalan independence in the northeastern region of Spain.

The judge is looking for evidence of collaboration between the pro-separatist parties Convergencia Democratica de Catalunya (CDC) and Ezquerra Republicana (ERC). He is also investigating the same sort of activity by pro-independence cultural groups, ANC and Omnium (whose leaders Jordi Sanchez and Jordi Cuixart are currently in prison facing investigation over charges of sedition) and the Association of Municipalities for Independence. The suspected collaboration would have taken place in the lead up to the independence referendum held in the region on Oct. 1, despite having been declared illegal by the Spanish Constitutional Court.

If evidence of collusion is uncovered, it could lead to more people facing criminal charges, such as rebellion, sedition and the misuse of public funds that former Catalan leader Carles Puigdemont is facing. Puigdemont is currently in exile in Belgium and his deputy Oriol Junqueras, who is in prison and has been denied bail.

Meanwhile, the latest opinion poll published in the La Vanguardia newspaper 11 days before the Dec. 21 regional elections called for Catalonia by Spanish Prime Minister Mariano Rajoy predict that pro-separatist parties will fall just short of a majority, winning 66 or 67 seats in the 135-seat regional assembly.