Madrid: Barcelona can extend their perfect start to the Liga season when they take on Las Palmas on Sunday in a game surrounded by political turmoil, as it occurs on the same day as a planned referendum in Catalonia on a break from Spain.

There was concern that the match would have to be postponed due to a lack of police resources as a result of the vote, which the Spanish government says is illegal, although it was given the green light at a meeting of Catalonia's security council on Thursday.

The Nou Camp has witnessed displays of pro-secession fervour in recent years, including chants of "independence" which take place after 17 minutes and 14 seconds in a match to mark the 1714 siege of Barcelona.

Barca defender Gerard Pique showed his support for the referendum on Thursday -- although he has never expressed his outright support for independence -- but urged citizens to behave in a peaceful manner.

"From today until Sunday we will express ourselves peacefully. We cannot give them any excuse, that is what they want. We will sing loud and clear. #WeWillVote," Pique wrote on his Twitter account.

Barca have positioned themselves in favour of the right to decide and released a statement last week condemning crackdowns on referendum activity which led to the arrest of 16 local government officials.

"It will be an important day in the history of our country but we have to focus on football," said Barca vice-president Jordi Cardoner.

"I think that all members, fans and supporters will express what they think is right."

Barca lead the Liga standings by four points over Atletico Madrid after winning six games from six and maintained their 100 percent start in Europe by scraping a 1-0 win at Sporting Lisbon on Wednesday.

They face a Las Palmas side who are 15th with six points from six games and reeling from the resignation of coach Manolo Marquez.

New coach Pako Ayestaran takes charge of his first game for the club and has sweet memories of his last visit to the Nou Camp, where his Valencia side stunned Barca by winning 2-1 in April 2016.

Las Palmas are facing an injury crisis with five players unavailable while Barca have no fresh concerns ahead of the game.

Also on Sunday, Real Madrid will search for their first home win of the season in the league when they host Espanyol, who have proved generous opponents in recent years, with Real winning the last 10 games between the two sides in all competitions.

Real have dropped points in their three home league games but will be buoyed by their impressive 3-1 win at Borussia Dortmund on Tuesday in the Champions League.

On Saturday, Atletico make the short trip to Madrid neighbours Leganes looking to bounce back from their last-gasp 2-1 defeat at home to Chelsea.