BARCELONA • Spain's Constitutional Court has suspended a session of the Catalan Parliament scheduled for Monday in which local leaders were expected to declare Catalonia's unilateral independence from Spain.

The ruling followed a legal challenge by the Catalan Socialist Party, which opposes secession, according to El Pais newspaper.

Judges "ordered the suspension of the plenary that has been called for Monday in the (Catalan) Parliament" while it hears an appeal lodged against it, a spokesman said, as the court confirmed the ruling in a written statement.

Spain's government has defiantly rejected calls for mediation over Catalonia's push for independence as the two factions headed towards another showdown.

The European Union has urged dialogue to ease the stand-off between separatists in the north-eastern region and Madrid, but Catalan leaders said they could unilaterally declare independence as early as Monday.

The tone of the crisis sharpened with Catalonia's president denouncing King Felipe's intervention and Spain's government rejecting any possible talks.

"The government will not negotiate over anything illegal and will not accept blackmail," said a statement from Prime Minister Mariano Rajoy's office on Wednesday.

"Negotiation in democracy only has one way, the way of the law."

The dispute is Spain's worst political crisis in decades and images of police beating unarmed Catalans taking part in Sunday's banned independence referendum sparked global concern.

The regional government said 42 per cent of the electorate voted on Sunday, with 90 per cent of those backing independence.

But polls indicate Catalans are split.

Catalonia's President, Mr Carles Puigdemont, called the central government's policies "disastrous" as the region's leaders pushed on with its bid to break away from Spain, angering Madrid and raising the risk of further unrest.

Big banks threatened yesterday to abandon Catalonia, with Spain's fifth-biggest bank, Sabadell, set to discuss whether to shift its legal domicile away from Catalonia in response to the crisis, a spokesman said.

The King on Tuesday 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.

Accusing them of "disloyalty", the King said that the state had to "ensure constitutional order".

Mr Puigdemont angrily rejected this, saying in a televised address: "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."

He also accused the national government of failing to respond to proposals for mediation in the crisis.

A declaration of independence would intensify the conflict with the central government, which along with the national courts has branded the referendum illegal.

Madrid has the power to suspend the semi-autonomous status that Catalonia currently enjoys under Spain's system of regional governments.

That would further enrage Catalan protesters, who say they are being repressed by Spain.

REUTERS, AGENCE FRANCE-PRESSE