Spanish police have been told to frisk at least 19,000 FC Barcelona football fans attending the Copa del Rey cup final in Madrid on Sunday to ensure they aren't carrying flags in support of Catalonia’s independence movement.

The government chief in the capital region said that the supporters of finalists Sevilla and Barça will be subjected to a complete body search to prevent the display of "inflammatory symbols" such as the yellow-and-red striped Catalan flag, known as the estelada.

The final “must not be made a scene of political struggle,” said Concepción Dancausa in announcing the special security measures on Wednesday.

Ms Dancausa said that 2,500 police officers will be on duty in and around the Vicente Calderón stadium for Sunday night’s match, which will be attended by 55,000 spectators and Spain’s King Felipe, who will present the season-ending trophy.

Spain’s conservative Popular Party (PP) acting government has argued in the past that the ‘estelada’ should be prohibited in stadiums as it can “provoke a violent reaction in some groups of fans”. But the banner is a familiar sight in Barcelona’s Camp Nou and when the club plays away from home.

Even if the police succeed in preventing pro-independence flags from being waved in the stadium, they will not stop thousands of Catalan fans booing and jeering the Spanish national anthem in the presence of the king, as has become customary in recent years when Barcelona has played the final.