Puigdemont said the Saturday decision by Prime Minister Mariano Rajoy to fire the regional government and force a new election, which will be effective next Friday, was "the worst attack against the institutions and the people of Catalonia since the military dictatorship of Francisco Franco".
Spain announced an unprecedented plan Saturday to sack Catalonia's separatist leaders, install its own people in their place and call a new local election, using previously untapped constitutional powers to take control of the prosperous region that is threatening to secede.
Rajoy could force the removal of Catalan officials and call early regional elections for as soon as January.
Spain's National Security Department said late on Friday that an undisclosed number of government websites had been hit in recent weeks with slogans supporting independence for the country's Catalonia region. This would happen happen in the coming days, Rajoy said.
Article 155 allows central authorities to intervene when one of Spain's 17 autonomous regions fails to comply with the law.
The Madrid government announced Thursday that it would invoke Article 155, a provision that allows the central government to suspend the autonomy of the Catalan regional administration.
Rajoy's Popular Party has a majority in the Senate.
"I ask the parliament to meet in a plenary session during which we, the representatives of the citizens' sovereignty, will be able to decide over this attempt to liquidate our government and our democracy and act in outcome", Puigdemont said in a televised speech.
Catalan president Carles Puigdemont was among the huge crowds filling the streets around the Paseo de Gracia boulevard, with many chanting "independence" and "freedom".
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In an unusually emotional speech at a prize-giving ceremony, he said the Spanish government would resolve the fight over Catalonia's bid for independence through "legitimate democratic institutions".
Activist organizations ANC and Omnium have called on their supporters to rally at 1500 GMT in Barcelona, the region's principal city, in protest at the jailing of their leaders over sedition accusations.
European Union leaders have backed the Madrid government in its handling of the crisis, which Rajoy insists is an internal matter.
Speaking Thursday, Puigdemont said that if Madrid "persists in blocking dialogue and the repression continues", the Catalan parliament reserved the right to formalize a declaration of independence that was suspended on October 10. Such actions are expected to spark angry opposition from supporters of independence and moderate Catalans who will see them as an attack on their autonomy.
Ninety percent of those who voted approved of independence, according to the regional government.
The country's Constitutional Court has so far ruled against all moves toward secession, including the Catalan referendum.
Amid the uncertainty, businesses have started to move their legal headquarters out of Catalonia, Spain's wealthiest region.
Spanish authorities are preparing to arrest Catalonia's president and charge him with rebellion if he declares independence.