BARCELONA, Spain (AP) – Police are guarding public buildings and closing off a park surrounding the regional Catalan parliament in Barcelona where a declaration of independence on Tuesday evening is likely to be met with a harsh response from Spanish central authorities.

Catalan president Carles Puigdemont hasn’t revealed the precise message he will deliver in a 6 p.m. (1600GMT) plenary session, but separatist politicians have said they expect a declaration based on the results of the disputed Oct. 1 independence referendum.

The separatists have declared valid the pro-independence victory in the vote, which was followed by mass protests of Catalans angered by heavy-handed police tactics.

There have also been large-scale rallies by people committed to national unity.

How the declaration will be enforced and what the Spanish government’s response will be are the key questions.