Catalonia's governing nationalist coalition has published a proposal for the region to obtain sovereignty while remaining part of Spain.
Catalonia's nationalists want to compete in international sport
The draft statute on autonomy is part of the coalition's campaign for re-election in October.
It is expected to be matched in the coming weeks by the rival Socialist Party.
The Socialists do not use the word "sovereignty" but correspondents say that they have similar ambitions - including a desire to wring more money from central government.
Unlike Catalonia's third-largest party, Esquerra Republicana, neither group seeks independence.
The proposal from the nationalist Convergence and Union (CiU) coalition, which has been in power for 23 years, calls for:
- increased tax-raising powers
direct Catalan representation at EU level
Catalan representation in international sporting competitions
obligatory knowledge of Catalan language for all people living in the region
At the same time, it recognises that the Spanish state is Catalonia's "framework of political organisation".
Basque 'free association'
The Madrid-based national daily newspaper El Pais said on Monday that the proposal goes beyond what the Spanish constitution permits.
The national governing Popular Party dismissed it as "electioneering", as did the Socialist Party - despite the fact that its Catalonian sister party is developing an analogous plan.
The Catalonian election in October will be followed by a national election next spring.
The proposal from the nationalists echoes a call by Basque leaders in September for free association between the Basque region and Spain.
The Basque regional parliament is scheduled to debate the plan by the end of the year.
The Basque region, and neighbouring Navarra, have long raised all their own taxes, and agreed with Madrid on the sum to be sent to central government coffers.
The Catalan nationalists are seeking the same arrangement.