Pro-independence Catalans gathered on the streets of Barcelona Tuesday ahead of a hotly anticipated speech by the region's leader on the status of the restive province.
Carles Puigdemont, the President of Catalonia, is under intense pressure to back down from plans to declare independence from Spain following a disputed referendum.
Puigdemont was due to address a specially convened session of the region's parliament. The session, due to begin at 12 p.m. ET (6p.m. local time) was delayed by an hour, reports CNN.
The Parc de la Ciutadella, which houses the Catalan parliament building, was sealed off to the public for safety reasons, with the Catalan police Mossos guarding the entrances and exits.
National police and the Guardia Civil kept a low profile.
European Council President Donald Tusk urged Puigdemont to back down. "The force of arguments is always better than the argument of force," he said in Brussels.
"Today I ask you to respect in your attentions the constitutional order and not announce a decision that would make such a dialogue impossible," he said. "Diversity should not lead to conflict whose consequences would be bad for Catalonia, Spain and the whole of Europe."
Mayor of Barcelona Ada Colau, an influential figure who has been critical of both sides, called for de-escalation. She urged Puigdemont not to make a unilateral declaration of independence, and also called on the government of Prime Minister Mariano Rajoy not to impose direct rule from Madrid. "Now is the time for dialogue," she said in address from in Barcelona.
Colau said Spain was experiencing its "worst institutional crisis since democracy began" and said Spain's political elected representatives should "find a solution that is inclusive and up to standards we have been living."
Neighbouring France said Monday it would not recognise an independent Catalonia -- and independence would result in automatic expulsion from the European Union.