Barcelona (AFP) - The leader of Spain's Catalonia region, where a separatist movement is in full swing, on Friday announced an independence referendum for October 1 in defiance of Madrid which is firmly against such a vote.

Speaking in Barcelona, Carles Puigdemont said the question would be: "Do you want Catalonia to be an independent state in the form of a republic."

Catalonia, a wealthy, 7.5-million-strong region with its own language and customs, has long demanded greater autonomy.

Separatist politicians in the northeastern region have tried for years to win approval from Spain's central government for a vote like Scotland's 2014 referendum on independence from Britain, which resulted in a "no" vote.

And while Catalans are divided on the issue, with 48.5 percent against independence and 44.3 percent in favour according to the latest poll by the regional government, close to three-quarters support holding a referendum.

But Catalan authorities have repeatedly been thwarted in their attempts to hold such a vote, arguing it goes against the constitution and would threaten the unity of Spain.

In 2014, Catalonia held a non-binding vote under then president Artur Mas, in which more than 80 percent of those who cast a ballot chose independence, although just 2.3 million out of 6.3 million eligible voters took part.

But in holding the symbolic referendum, Mas went against Spain's Constitutional Court, which had outlawed the vote -- even if it was non-binding.

He was later put on trial and banned from holding office for two years.

Puigdemont, though, still wants to go ahead, and he wants his referendum to be binding this time -- even though Madrid has pledged to be just as tough this time round.