Catalonia’s civil servants face their first full working week since Spain’s central government overturned a declaration of independence by firing the region’s elected leaders.

All eyes will be on whether the transfer of power will be smooth or face opposition, which could deepen a month-long political crisis.

There was no sign of whether ousted regional leader Carles Puigdemont and other members of his deposed cabinet would try to go to their offices on Monday, after the regional parliament proclaimed independence from Spain in a secret ballot on Friday.

TV crews stand in front of the Palau Generalitat as they wait for the arrival of the Catalonia president Carles Puigdemont, in BarcelonaTV crews stand in front of the Palau Generalitat as they wait for the arrival of the Catalonia president Carles Puigdemont, in Barcelona (Manu Fernandez/AP)

Mr Puigdemont has vowed peaceful and “democratic opposition” to his cabinet’s dismissal, but he has not clarified if that means accepting an early regional election as a way out of the deadlock.

He is likely to be accused of rebellion on Monday for pushing ahead with secession.

Mr Puigdemont posted a photo on social media of a courtyard at the seat of the regional government in Barcelona.

The ambiguous Instagram post, accompanied by the words “Good morning” in Catalan and a smiley emoticon, left many guessing if Mr Puigdemont was inside the premises.

As speculation raged about the whereabouts of Mr Puigdemont and his deposed cabinet, separatist parties and grassroots groups spoke of waging a campaign of disobedience to hamper the efforts by central authorities to run the region.

A key factor will be how Catalonia's estimated 200,000 public workers react to their bosses' dismissal, and whether any stay away from work in protest.

Secession moves by the wealthy north-eastern region of 7.5 million people have tipped Spain into its deepest crisis in decades.

On Sunday, hundreds of thousands took part in an anti-independence demonstration in Barcelona, calling for Catalonia to remain in Spain and backing prime minister Mariano Rajoy's use of unprecedented constitutional powers to seize control from the pro-independence regional administration.

"We won't let Spain be torn apart into pieces," read one banner. "The awakening of a silenced nation," read another.

"We have organised ourselves late, but we are here to show that there is a majority of Catalans that are no longer silent and that no longer want to be silenced," said Alex Ramos, head of Catalan Civil Society, a pro-union grassroots group.

The organisers said more than one million people turned out but police put the figure at 300,000.

Many who oppose independence fear the political turmoil in Catalonia could have a severe economic impact, both in the region and on Spain itself.

Some 1,700 companies have already relocated their headquarters to other parts of Spain in recent weeks amid the uncertainty.