Catalonia's separatist leader has refused to say whether he has declared independence from Spain, with Madrid calling for a definitive answer by Thursday.

Spain had demanded a yes or no answer by 10.00am on Monday after the controversial referendum on October 1st sparked the country's worst political crisis in a generation.

But in response, Catalan President Carles Puigdemont wrote a letter to Spanish Prime Minister Mariano Rajoy - calling for a meeting "as soon as possible".

Stopping short of giving a "yes or no" answer, the politician wrote: "Let's not let the situation deteriorate further. With good will, recognising the problem and facing it head on, I am sure we can find the path to a solution."

Last week, Mr Rajoy had warned that Madrid would suspend Catalonia's autonomy if independence was declared.

He had also warned that any ambiguous response would be considered as confirmation that a declaration of independence had been made.

Speaking on Monday morning, Spain's Deputy Prime Minister said the government response had wide backing in the Spanish parliament, and demanded Mr Puigdemont say by Thursday whether he would be declaring independence.

Divisive referendum 

A declaration of independence would trigger Article 155 of the 1978 constitution - allowing Madrid to impose direct rule, sack the local administration and appoint a new governing team who will take control of the police and the wealthy region's finances.

About 90% of those who voted in the referendum backed separating from Spain, but only around 40% of people turned out, with most of those who reject secession boycotting it.

Mr Puigdemont is under pressure from multiple sides over a possible declaration.

Pro-independence parties within his own government have said they will walk away from his coalition if he fails to make an unequivocal statement of independence.

But hundreds of companies have indicated they will move operations from Catalonia if the region separates, fearing the impact of the consequent split from the European Union.

In the days after the referendum, Mr Rajoy's government introduced a new law to make it easier for companies to relocate in what many saw as a tactic to frighten the separatists.

The two biggest banks in Catalonia have already moved their legal headquarters to other parts of Spain, with credit agencies warning the country could be tipped into recession if the crisis continues.

The Spanish Prime Minister has been criticised for his hard line on Catalonia, with European Council President Donald Tusk among those who have urged him to talk with Mr Puigdemont.