Spain's state prosecutor called for rebellion and sedition charges to be brought against Catalonia's leaders on Monday over their push to separate from Spain.
Attorney-General Jose Manuel Maza also called for charges of misuse of funds to be laid.
Under Spain's legal system, the request goes to a judge for consideration. Maza asked the judge to call the seccessionist leaders to tesify.
Work resumed normally in Catalonia and calm reigned on the streets on Monday despite calls for civil disobedience from secessionist politicians, in early signs the direct rule imposed to stop an independence bid was taking hold.
Although some public sector workers have yet to tell their new bosses whether they will accept orders, the lack of unrest came as a relief for financial markets, which rose.
Spanish Prime Minister Mariano Rajoy assumed direct control of the region on Friday, fired its secessionist government and called a snap election for December 21.
Catalan pro-independence party Esquerra Republicana de Catalunya will take part the election, it said on Monday, in a tacit admission that the previous ruling party in Catalonia had been fired and parliament dissolved.
"Taking part in December 21 is an opportunity to better consolidate the Republic ... They've called illegitimate elections, a trap. However, we're not afraid of the ballot box," lawmaker Sergi Sabria said during a conference.
However, some of the most prominent members of the Catalan administration, including its president, Carles Puigdemont, and vice-president, Oriol Junqueras, had said they would not accept the move and only the people of Catalonia could dismiss them.
The main civic groups behind the pro-independence campaign had called for widespread civil disobedience, and said that public sector workers such as teachers, firefighters and the police should refuse orders from the central authorities.
But most workers started their working day at 9 A.M. local time as normal and there was no sign of widespread absenteeism.
Most fired Catalan leaders remained ambiguous on Monday and stopped short of directly defying Spain's authority. There were no signs of any spontaneous demonstration taking place.
Puigdemont posted a picture on Instagram taken in the regional government headquarters, but was not seen entering, suggesting the photo may have been taken by someone else.
Regional transport chief Josep Rull posted on Twitter a picture of him working in his office but he was later seen leaving the building. Spain's transport minister had said in a radio interview Rull would be allowed to collect his personal belongings but not work there.
When he left, Rull said he would now attend a meeting of the PdeCat, or the Catalan Democratic Party.
"Let's go on with the scheduled agenda," he said.
'Things have to carry on'
Other regional leaders did not turn up to their offices though some of their staff did. One of 140 senior officials appointed directly by the outgoing government described the situation as "normal" and said he had not yet received any letter of dismissal.
"We civil servants want everything to be normal. Things have to carry on. The day-to-day work still has to be done," said the official, who works with the outgoing vice-president, Junqueras.
Two hundred thousand public sector workers receive salaries paid by the Catalan region, and another 100,000 in the region rely directly on the Madrid government.
Hundreds of thousands of supporters of a unified Spain marched on Sunday in one of the biggest shows of force yet by the so-called silent majority that has watched as regional political leaders push for Catalan independence.
Two opinion polls also showed support for independence may have started to wane. A Sigma Dos survey published in El Mundo showed 33.5 percent Catalans were in favor of independence while a Metroscopia poll published by El Pais put that number at 29 percent. This compared to 41.1 percent in July according to an official survey carried out by the Catalan government.
Opponents of secession largely boycotted the October 1 referendum, when participants voted overwhelmingly for independence on turnout of 43 percent.
Spain's interior ministry named a new chief for the regional police on Saturday who has insisted that the 17,000 officers of the force should remain neutral. Interior Minister Juan Ignacio Zoido was due to meet the new police chief in Madrid on Monday.
The force has already withdrawn protection for fired regional government members, who were also left without their official cars. Their portraits were removed from the walls of public buildings.
The government's move to impose direct rule received the backing of several influential Catalan business lobbies, which called on firms to stay in the region. The chaos has prompted an exodus of businesses from Catalonia, which contributes about a fifth of Spain's economy.
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