Barcelona’s city council said they had been paid €94,000 by giant sports brand Nike for the advertising campaign.
But local left and right wing politicians have attacked Barcelona’s mayor Xavier Trias for allowing a public monument to carry publicity.
“No monument, temple, statue, fountain, green area or public service can carry any form of advertising by law,” said PSC socialist spokesperson Gabriel Colomé.
“Nike missed out on a great chance to promote Barça’s brand new away jersey with the senyera (Catalan flag) colours,”Colomé told Catalan newspaper La Vanguardia in a sarcastic tone.
“Mayor Trias is the only one to blame,” Espanyol president Joan Collet told Madrid sports daily Marca.
“Two weeks ago he said that having a son-in-law who was an Espanyol fan would be a tragedy. We’re fed up of being looked down on.
“Imagine if the Trevi fountain had a Rome jersey put on it. These things only happen here.”
Some Espanyol fan groups have issued an official statement saying they will turn their backs and whistle when their team welcome Barça as league champions with the traditional guard of honour at this Sunday's Catalan derby.