"The king has adopted the (national) government's position and policies which have been disastrous with regard to Catalonia. He is deliberately ignoring millions of Catalans," Carles Puigdemont said in a televised address.
As the European Union urged dialogue to ease the standoff between separatists in the northeastern region and Madrid, a regional government source said the independence declaration could be as early as Monday.
The standoff has morphed into Spain's worst political crisis in decades, with images of Spanish police beating unarmed Catalans taking part in Sunday's banned independence vote sparking international concern.
The region's leaders have pushed on with their bid to break away from Spain, angering Madrid and raising the risk of further unrest.
Spain's key IBEX 35 stock index plunged by more than three percent Wednesday in the ongoing turbulence, with some big Catalan banks down more than five percent.
"Political risk is back on the agenda in Europe," NFS Macro analyst Nick Stamenkovic told AFP.
Independence debate likely on Monday
After meetings in the regional parliament on Wednesday, pro-independence lawmakers called for a full session next Monday to debate the final results of the vote.
"According to how the session goes, independence could be declared," a regional government source told AFP, speaking on condition of anonymity.
Mireia Boya of the radical leftwing separatist CUP said it would be "a plenary to proclaim the republic" of independent Catalonia.
President of the Catalan parliament Carme Forcadell, center, attends a meeting with parliament representatives at the Catalonia Parliament in Barcelona. Source: AAP
King Felipe VI earlier branded the independence drive illegal and undemocratic, throwing his weight behind the national government.
Catalan leaders "with their irresponsible conduct could put at risk the economic and social stability of Catalonia and all of Spain," he said.
But still Catalan President Carles Puigdemont has dug in and is scheduled to give a televised address today.
'Fuel to the fire'
King Felipe repeated his earlier calls for harmony between Spaniards.
But after Sunday's violence it risked further fanning resentment in Catalonia.
"The king's speech was irresponsible," said Turull.
"Instead of calming things, what it did was throw fuel on the fire."
People watching in a bar in Barcelona whistled and booed after the king's speech.
"He did not say a word about the people who were injured," said Domingo Gutierrez, a 61-year-old trucker.
"I have never been pro-independence, my parents are from Andalucia. But now I am more for independence than anyone, thanks to people like that."
Catalan 'sedition' probe
Adding to tensions, a judge on Wednesday placed Catalonia's regional police chief Josep Luis Trapero and three other suspects under investigation for an alleged "crime of sedition."
The force has been accused of failing to rein in pro-independence protesters during disturbances in Barcelona last month.
The judge leading the judicial investigation, Carmen Lamela, also summoned the leaders of two prominent Catalan pro-independence civil groups: Jordi Cuixart of Omnium Cultural and Jordi Sanchez of the Catalan National Assembly (ANC).
The fourth suspect is another senior police official.
Catalans split
A rich industrial region of 7.5 million people, Catalonia accounts for a fifth of Spain's economy.
It has its own language and cultural traditions.
Its claims for independence date back centuries but have surged during recent years of economic crisis.
Puigdemont's regional government claimed that 2.26 million people took part in the poll, or just over 42 percent of the electorate.
The vote was held without regular electoral lists or observers.
The regional government said 90 percent of those who voted backed independence, but polls indicate Catalans are split.
Puigdemont has called for international mediation in the crisis. The European Union's executive commission has voiced concern.
The European Parliament was scheduled to debate the Catalonia crisis later on Wednesday.
