While it will not come as a surprise to anyone following ongoing events in Spain, moments ago the country's Constitutional Court said on Tuesday the referendum law passed by the Catalan government Sept. 6 to hold a vote on independence was unconstitutional and void, a spokesman said. The court's full statement can be found here, while the opinion is at this link.
The court had originally suspended the referendum law as it studied its legality, though the Catalan government went ahead with the ballot regardless.
According to the Court, the Catalan legislation, approved by the region on Sept. 6 and suspended by the court the following day, usurped powers of the State to hold referendums. It also violated the principle that the Spanish nation is indissoluble.
In other words, this is the definitive confirmation from Spain that any Catalan separation is not possible, nor legal.