World Bulletin / News Desk

The Spanish government warned Catalonia's separatist leader on Tuesday not to do anything "irreversible", just hours before a possible declaration of independence that could send shockwaves through Europe.

But the Spanish government issued a sharp warning to Puigdemont on Tuesday as it grapples with the nation's worst political crisis in a generation.

"We call on Puigdemont not to do anything irreversible, not to pursue a path of no return and not to make any unilateral independence declaration," government spokesman Inigo Mendez de Vigo told reporters.

Speaking soon after, Catalan government spokesman Jordi Turull retorted that the regional executive was "completely united", without giving any hint of what Puigdemont may tell Catalan lawmakers in an extraordinary parliamentary session beginning at 1600 GMT.