Catalonia's main separatist parties have proposed holding a new referendum on a constitution of the "Catalan republic" which was declared in October but never came into effect.
In an agreement seen by AFP on Thursday, they also propose establishing a parallel Catalan government headed by the region's ousted president Carles Puigdemont in Belgium.
Puigdemont moved to Belgium after the Catalan parliament unilaterally declared independence on October 27 following a banned referendum on secession.
The agreement between Catalonia's two main separatist parties, Puigdemont's Together for Catalonia and the leftist ERC, still needs to be ratified by the small far-left separatist CUP party.
It also calls for the launch of a participative process to define what an independent Catalonia should look like, which would lead to the creation of a "future Constitution of the Catalan Republic".
The process would conclude with a referendum that would give Catalans the chance to vote on each paragraph of the proposed constitution.
This vote would likely be deemed illegal like the October 1 independence referendum, which was marred by police violence at some polling stations.
The separatists would also create in Belgium a "free space in exile", a body chaired by Puigdemont whose goal would be to "promote the internationalisation of the cause of the independence of Catalonia" and "move towards the establishment of the Catalan Republic" in coordination with Catalonia's regional government in Barcelona.
"The cause of Catalonia emerges today as the just cause of all people who want to be free," the agreement reads.
Catalan separatist parties won an absolute majority of seats in the 135-seat Catalan parliament in a snap election on December 21 but have so far failed to form a new government.
Catalonia's parliament will convene on March 12 to appoint a new regional president, but the outcome is uncertain with jailed separatist Jordi Sanchez the only candidate. To be sworn in Sanchez would need to obtain permission to leave prison, which appears unlikely.
The separatists' push for independence plunged Spain into political crisis last year.
The Spanish government imposed direct rule over the region on October 27 after the Catalan parliament unilaterally declared independence.
Direct rule is due to last until the region elects a new president. Madrid has vowed to resist any bid to break the region away from Spain.