The Spanish Government is holding an emergency meeting this morning after Catalonia's president signed a document declaring the region's independence.
In a much anticipated address yesterday, the region's leader Carles Puigdemont insisted Catalans had earned the right to independence.
However he delayed the declaration for several weeks in an effort to give dialogue with Madrid a chance.
However the Spanish Deputy Prime Minister Soraya Saenz de Santamaria immediately rejected any notion of talks following a referendum his government deemed illegal.
He claimed Mr Puigdemont "doesn't know where he is, where he is going and with whom he wants to go."
The Spanish Cabinet is expected to examine ways to respond to the Catalan declaration – with the "nuclear option" of suspending the region's autonomy and sending in the national police reportedly one of the options under consideration.
The move would be a risk for Spanish Prime Minister Mariano Rajoy – and could fan the flames of the independence movement.
The brutality of the police response to the Catalan referendum came in for international criticism – and many Catalans would be strongly opposed to an increased national police presence.
Some 900 people were injured as police attempted to prevent people from casting their ballots in the October 1st vote.
Catalonia's government said that of the 2.2 million voters who were able to vote - two million voted for independence.
Mr Rajoy will want to be seen to be sticking to his hard line against the independence movement when he addresses an extraordinary session of parliament this afternoon.
He has not ruled out arresting Mr Puigdemont and other pro-independence figures – however again the move would risk adding fuel to push for separation.
He has come under pressure to soften his stance on negotiations and European Council President Donald Tusk is among the latest to urge him to sit across the table from Mr Puigdemont.
The Catalan leader's speech seemed to be cast in overtures of compromise as he said separatists have nothing against Spain or Spaniards.
Mr Puigdemont added: "We're not criminals, we're not mad. We're normal people who want to vote."
Despite this, the signing of an independence declaration will be viewed by Madrid as an act of provocation and Mr Rajoy will struggle to find response that satisfies all of his support.