CATALAN authorities resisted an attempt by Spain's central government to take control of the regional police force yesterday amid rising tensions ahead of a planned independence vote.

The Catalan Government has vowed to push ahead with the referendum on October 1 which the Spanish government considers illegal. It said it was refusing to hand over control of the Mossos d'Esquadra police force to Spain's Interior Ministry.

The Ministry had announced yesterday it would begin coordinating all police efforts in Catalonia to crack down on preparations for the vote, including sending direct orders to the 'Mossos' — as the northeastern region's largest police force are often called.

Joaquim Forn, the head of Catalonia's Interior Department in Barcelona and the civilian head of the Catalan police, said in a statement on regional television that the move would be “unacceptable”.

He said, "We denounce the attempt by the state to intervene in the police forces of Catalonia.”

The statement followed a meeting yesterday with the top state prosecutor in Catalonia and chiefs of Spain's two national police forces, the National Police and the Civil Guard.

A statement posted on the Mossos official Twitter account said: "We will continue working like we've done until now. We will exercise our powers to guarantee security and public order and be at the service of citizens."

Spain has already said it will deploy police reinforcements to Catalonia if the independence referendum goes ahead.

Last week Civil Guard police arrested around a dozen regional government officials and seized about 10 million ballot papers. Authorities in the wealthy region insist the vote will take place, even though Spain's Constitutional Court has ordered it to be suspended and the Madrid-based national government insists it is illegal.

An Interior Ministry statement said the extra police would provide backing for the Catalan regional police, who are also under orders to prevent the staging of the referendum.

The statement said the Catalan Interior Ministry had been informed. It did not say how many extra police would be sent. Three ferries docked at Barcelona's port will provide accommodation for the extra officers.

Spain's central government insists the planned referendum violates Spain's constitution, and the Constitutional Court has ordered it suspended while it studies its legality.

Catalonia represents a fifth of Spain's 1.1 trillion euro (£970 billion) economy and enjoys wide self-government.

The region has about 5.5 million eligible voters, and polls consistently show the region's inhabitants favour a referendum but are roughly evenly divided over independence from Spain.