Catalonia will move on Monday to declare independence from Spain after holding a banned referendum, pushing the European Union nation toward a rupture that threatens the foundations of its young democracy.

Catalan President Carles Puigdemont said he favoured mediation to find a way out of the crisis, but that Spain's central government had rejected this. Prime Minister Mariano Rajoy's government responded by calling on Catalonia to "return to the path of law" first before any negotiations.

Mireia Boya, a Catalan lawmaker from the pro-independence Popular Unity Candidacy party, said a declaration of independence would follow a parliamentary session on Monday to evaluate the results of the Oct. 1 vote to break away.

"We know that there may be disbarments, arrests.… But we are prepared, and in no case will it be stopped," she said on Twitter.

In a televised address on Wednesday night, Puigdemont said: "This moment calls for mediation. We have received various offers in the last hours and we will receive more. All of them know I am ready to start a mediation process."

Then he said, "Dialogue and agreement are part of the political culture of our people. However, the state has not given any positive answer to those offers."

Without specifically mentioning plans for an independence declaration, he added: "I am sure that in the next few days we will show the best of our country when the institutions of Catalonia will have to apply the results of the referendum.

"Today we are closer than yesterday to our historic wish."

Spain's Prime Minister Mariano Rajoy delivers a statement at the Moncloa Palace in Madrid on Oct. 1. Puigdemont called Rajoy's government 'irresponsible' for not accepting mediation in the deadlock. (Sergio Perez/Reuters)

Rajoy's government replied that Puigdemont had wasted an opportunity to put Catalonia back on a legal course. "If Mr. Puigdemont wants to talk or negotiate, or wants to send mediators, he knows perfectly well what he must do first: Return to the path of the law," it said in a statement.

Spain was only restored to democracy following the death in 1975 of military dictator Francisco Franco, under whom the Catalan language and traditions were suppressed.

Critical of the king

Puigdemont criticized Spain's King Felipe VI, who on Tuesday lambasted the "irresponsible behaviour" of the Catalan leaders.

People, one of them with a Catalan independence flag around her shoulders, watch Spain's King Felipe's TV address about the situation in Catalonia in Barcelona on Tuesday night. (Manu FernandezAssociated Press)

He said the king had disappointed many people in Catalonia by failing to call for dialogue and he accused Felipe of endorsing the policies of Rajoy, which he said had been "catastrophic" for Catalonia.

Puigdemont also said the king had failed to perform "the role of moderator."

The Catalan president said both the government in Madrid and the king "ignored deliberately the Catalans who have been victims of the police violence that has stopped the hearts of half the world."

"Mr. Puigdemont has been outside of the law for way too long," Rajoy's deputy, Soraya Saenz de Santamaria, said, responding to the remarks Puigdemont made in the televised address.

Spanish Deputy Prime Minister Soraya Saenz de Santamaria in Spain's parliament with Prime Minister Mariano Rajoy on May 31, said Wednesday 'Mr. Puigdemont has been outside of the law for way too long.' (Juan Medina/Reuters)

Attempts to find a mediated solution

The EU executive called again on Wednesday for the Spanish government and Catalan authorities to open a dialogue. "It's time to talk," the European Commission's deputy head, Frans Timmermans, told the European Parliament.

Various attempts to find a mediated solution to the crisis emerged on Wednesday.

Pablo Iglesias, leader of the left-wing Podemos party, proposed the Spanish and Catalan government try to agree on a mediator while the FC Barcelona football club said it had joined other groups in Catalonia seeking a negotiated solution.

Spanish media reports said the Catalan regional government had been in touch with senior church figures to sound out the possibility of them playing a mediating role.

Childhood friends David Jovellar, 24, wearing an independence flag and Almudena Chueco, 23, wearing a Spanish flag hug as they bumped into each other at a demonstration in Barcelona on Tuesday. (Emilio Morenatti/Associated Press)

But the Spanish government rejected mediation.

Rajoy told Iglesias that Puigdemont had to give up the idea of unilaterally declaring independence, a government source said. "That is not negotiable. You can't deal with people who plan to blackmail the state so brutally," the source added.

Rajoy, a conservative who has taken a hard line on Catalan independence, is considering the unprecedented step of dissolving the Catalan parliament and triggering regional elections, ruling party lawmakers say.

But he is struggling to secure support from across the traditional political divide — a lack of consensus that could compound Spain's worst political crisis for decades.

Spain could impose martial law

Rajoy's conservative government has pledged to respond with "all necessary measures" to counter Catalan defiance, without revealing how it intends to do so.

It's anybody's guess what might happen if the prosperous northeastern region does actually try to secede. Spain could intervene to take over the regional government; it could even declare a state of emergency and impose martial law.

A Spanish riot police officer shoots a rubber bullet at people trying to reach a voting site at a school assigned to be a polling station by the Catalan government in Barcelona on Sunday. (Emilio Morenatti/Associated Press)

In a sign that Spanish police reinforcements sent to Catalonia might be there for an extended stay, an army logistics unit sent bunk beds, kitchens and showers to an army barracks near Barcelona in case the police need to use the military base at some point, a ministry of defence spokesman said.

Some police staying at hotels in Catalonia have come under pressure from local residents to leave.

The route to becoming independent won't be easy for Catalonia. The region doesn't have any power over defence, foreign affairs, taxes, ports or airports, all of which are in the hands of the Madrid government. The European Union has also said that an independent Catalonia cannot stay in the bloc, but must apply to join — a lengthy, uncertain process.

Perhaps hinting at compromise, in his TV address Puigdemont said Catalonia "wants to continue contributing to the development of the Spanish state."

People shout and wave the Catalan flag during a protest outside National Police main station in Barcelona on Tuesday. (Susana Vera/Reuters)

Xavier Garcia Albiol, Rajoy's party deputy in Catalonia, called Wednesday for Catalans who want to stay inside Spain to join a rally Sunday in Barcelona, the region's main city.

Spain's National Court, meanwhile, said it will quiz two senior officers of Catalonia's regional police force and the leaders of two pro-independence civic groups who have been placed under investigation for sedition.

Financial markets hit

The constitutional crisis in Spain, the eurozone's fourth-biggest economy, has shaken the common currency and hit Spanish stocks and bonds. Madrid's borrowing costs have risen sharply and reached their highest since March on Wednesday.

The cost of insuring against potential losses on Spanish bank debt and Spanish, Italian and Portuguese sovereign debt has also jumped, suggesting an impact on the wider eurozone.

Spanish riot police swings a club against would-be voters near a school assigned to be a polling station by the Catalan government in Barcelona, Oct. 1. (Manu Fernandez/Associated Press)

Bank stocks were hit especially hard as the Ibex stock index fell below 10,000 points on Wednesday for the first time since March 2015. In a sign of the nervous public mood, Catalonia's biggest bank, Caixabank, and Spain's economy minister had earlier sought to assure bank customers that their deposits were safe.