The referendum, declared illegal by Spain's central government, has thrown the country into its worst constitutional crisis.

Catalonia will declare independence “in a matter of days", the region's secessionist leader Carles Puigdemont was quoted as telling the BBC, a move that would defy Madrid and attempt to implement the directive of Sunday's banned independence referendum.

Mr. Puigdemont said that his government would “act at the end of this week or the beginning of next", according to an interview with the BBC on Tuesday. (http://bbc.in/2fHFQJx)

When asked by the BBC what Mr. Puigdemont would do if the Spanish government were to intervene and take control of Catalonia's government, he said it would be “an error which changes everything". http://bbc.in/2fHFQJx

The regional leader opened the door to a unilateral declaration of independence from Spain on Sunday after voters defied a violent police crackdown and, according to regional officials, voted 90 percent in favour of breaking away.

The referendum, declared illegal by Spain's central government, has thrown the country into its worst constitutional crisis in decades and raised fears of street violence as a test of will between Madrid and Barcelona plays out.

Catalan President Carles Puigdemont told the BBC that his government would ask the region's parliament to declare independence after tallying votes from last weekend's referendum, which Madrid deems illegal.

His comment appeared after Spain's King Felipe VI accused secessionist leaders on Tuesday of shattering democratic principles and dividing Catalan society, as tens of thousands protested against a violent police crackdown on Sunday's vote.

“We are to declare independence 48 hours after all the official results are counted,” Mr. Puigdemont said in remarks posted on the BBC's website.

“This will probably finish once we get all the votes in from abroad at the end of the week and therefore we shall probably act over the weekend or early next week.”

Mr. Puigdemont is due to make a statement at 9 p.m. (1900 GMT) on Wednesday.