Spanish Prime Minister Mariano Rajoy has urged Catalans to turn out in large numbers to vote in a snap election next month, as he made his first visit to Catalonia since the central government of Spain imposed direct rule over the region.

Rajoy travelled to Barcelona on Sunday to campaign ahead of the December 21 regional poll.

"We want massive voting ... so we can start a new political era of tranquillity, normality, conviviality, with respect to the rules of the game and also of economic recuperation," Rajoy, leader of Spain's Popular Party, told supporters.

The Spanish leader said the vote next month would safeguard the region's economy and stop companies moving out of Catalonia.

"We must recuperate Catalonia from the many damages inflicted by the separatists. Separatism has unleashed insecurity and uncertainty, and both feelings are pushing the exodus of financial institutions to other regions in Spain," he said.

More than 2,000 companies have moved their headquarters from the northeastern region due to fears of being cast out of the European Union's common market in case Catalonia secedes. Employment figures have also shown that region fell behind other parts of the country in October.

Catalonia's parliament voted last month in favour of declaring independence from the rest of the country in the wake of an October 1 referendum that Spanish authorities had declared illegal.

In response, Madrid fired Catalonia's government, dissolved its parliament and called the early election.

"We've done exactly what any other country who respects itself would have done," said Rajoy. "What would France or Germany do if one of their regions suddenly wanted an autonomous referendum?"

Al Jazeera's Jonah Hull, reporting from Barcelona, said Rajoy was in the region to defend his decision to sack separatists leaders and call on his party supporters to come out and vote next month.

"He is somewhat of a hate figure to a large part of the population in Catalonia who support independence and secession. But Rajoy was here very much preaching the faithful and members of his own party," Hull said.

"He was calling on the silent majority, as they call themselves here, the other half of the population that favour the unity of Spain, to neutralise the independence movement," Hull said.

Rajoy's speech in Barcelona came a day after 750,000 Catalans took to the streets in a show of solidarity for eight former regional ministers jailed on charges of rebellion and sedition, two imprisoned civil society leaders and a government-in-exile in Belgium.