Catalan authorities declared on Tuesday (September 30) the temporary suspension of official campaigning for the planned referendum on independence from Spain.
The announcement brought scores of pro-independence demonstrators onto the streets of Barcelona.
A day earlier, the Spanish government had formally asked the constitutional court to declare the planned November vote illegal.
Prime Minister Mariano Rajoy said the poll would not be compatible with the Spanish constitution.
A final ruling has not yet been made, however on September 29, the court did decide to suspend the referendum.