By Sonya Dowsett and Sam Edwards
MADRID/BARCELONA (Reuters) - Hundreds of thousands of Catalans are expected to rally in the streets of Barcelona on Monday in what campaigners hope will be a show of support for independence after Madrid moved to block a planned referendum on the region's split from Spain.
The 'Diada' day of Sept. 11, which commemorates the fall of Barcelona to Spain in 1714, is often used by activists to voice their demands for an independent state. Coachloads of demonstrators travel to Barcelona from villages in the region.
Hostility between Madrid and Barcelona has ramped up since Spain's Constitutional Court last Thursday suspended the referendum, planned for Oct. 1, following a legal challenge by Prime Minister Mariano Rajoy.
The government says the referendum contravenes the constitution, which states that Spain is indivisible.
Catalan leader Carles Puigdemont has urged 'independentistas' to take to the streets on Monday in a massive show of support for the referendum.
"It's vital that we come out in force for this Diada for the Oct. 1 referendum to be successful," he said on Twitter. "I'll be there."
Spain's state prosecutor has begun criminal proceedings against Puigdemont and 13 members of his cabinet on charges of misuse of public money, disobedience and abuse of office after the Catalan parliament approved the referendum last Wednesday.
Rajoy has urged Catalan civil servants and mayors to uphold the law and to stop any preparations for the referendum over the next three weeks.
However, around two-thirds of Catalonia's mayors have so far said they will allow the use of municipal facilities for the vote, with one mayor ripping up a court order warning of legal repercussions in front of a cheering crowd.
Puigdemont has said he has ballot boxes and voting papers hidden and ready to deploy at any moment. Over the weekend, police searched a printing press and the offices of a local newspaper for signs of preparation for the referendum.
At the height of pro-independence fervor in 2012, during a deep economic recession in Spain, around one million people took to the streets waving the Catalan flag and singing the Catalan anthem.
Polls have shown support for independence waning since then, and those wanting a separate state are in a minority. However, a majority of Catalans want to hold a referendum on the issue.
(Reporting By Sonya Dowsett; Editing by Gareth Jones)