MADRID (REUTERS) - Tens of thousands of Catalans crowded central Barcelona on Sunday calling for early regional elections after plans for a Nov 9 referendum on independence from Spain were declared illegal by Madrid.

People dressed in yellow T-shirts waved the red and yellow Catalan independence flag, marked with a white star, and bore banners reading "Now is the time" and "We are ready".

Some in the separatist movement want Catalonia's leader Artur Mas to call early regional elections as a proxy vote on secession, a move likely to benefit the more radical independence party ERC, a coalition partner of Mas's CiU party. "President, call elections, we want to vote in the next three months. We want to start in the spring of 2015 with a new parliament," said Carme Forcadell, head of pro-independence National Catalan Assembly as she addressed the crowds.

More than 100,000 people attended the demonstration, according to media reports. Police could not be reached to confirm this figure.

Mas said on Tuesday he had dropped plans to hold a referendum on independence from Spain but would instead hold a"consultation of citizens" with ballots and ballot boxes which he said would be within the law.

The Spanish government last month asked the constitutional court to declare the referendum planned for Nov. 9 illegal on the grounds it breached the constitution. The court suspended the vote until it ruled on the case, which could take years.

About half of Catalans want more independence from Spain and a vast majority favour holding a vote on their future, polls show.