GORDON Brown has warned Catalonia that independence is difficult to achieve in an increasingly globalised world.

The former Prime Minister said it was crucial to move the debate towards the real consequences of breaking away – and said Brexit posed as an example with voters now able to see through "slogans" which cannot be implemented.

Mr Brown was speaking at a conference in Madrid organised by El Confidencial, a Spanish news website, and investment management firm Pimco.

He said: “In a world economy, your independence is always going to be limited by your interdependence.

“We are interconnected and integrated. The idea you can just walk away from that is an impossibility in the modern world.”

Mr Brown said one of the problems of Brexit was that "nobody explained why” the UK would be poorer if it left the EU.

In Catalonia, however, he claimed the region had already been able to see the economic consequences of independence. These included the flight of business and a slowdown in tourism.

Spain has imposed direct rule on Catalonia since October's banned referendum, sacking the autonomous government and jailing some leaders.

Around 90 per cent of voters had backed independence in the poll, but turnout was low and Spanish police were widely criticised for their use of violence.

Ousted Catalan leader Carles Puigdemont, who is currently in exile in Belgium, is now facing possible extradition to Spain amid charges of sedition and misuse of state funds.