Barcelona's Camp Nou will attract worldwide attention for politics rather than football on a day of huge significance for Catalonia's future on Sunday.

Las Palmas are the visitors as Barca seek to stretch their perfect record in La Liga and Champions League this season to nine games.

However, the action on the field will play second fiddle with pro-secessionist politicians forging ahead with a planned referendum on independence for the wealthy north-eastern region of Spain despite the best attempts of the Spanish government, who have declared the vote illegal.

Outspoken central defender Gerard Pique called on people to vote peacefully with tensions heightened by a crackdown on those responsible for calling and organising the logistics for the vote to take place.

"From today until Sunday, we will express ourselves peacefully," Pique posted in a message in Catalan on his Twitter account on Thursday.

"Don't give them any excuse. It is what they want. And we will sing loud and clear. #Wewillvote