The animated duo are emblazoned over a cruise ship docked in Barcelona which is being used as emergency accommodation for 4,000 military police officers during unrest over the banned Catalan referendum.
But feathers were ruffled when pictures of the ship, the Moby Dada, were broadcast around the world.
Images of the vessel, complete with huge murals of Tweety Pie and Sylvester, appeared alongside hundreds of military vehicles and police intervention units.
And Warners Bros bosses went Loony Tunes.
They immediately called on the ship’s Italian owners Moby Lines to remove it from the port because they did not want the images of their cartoon characters linked with the Catalan crisis and the massive police deployment.
But the operators have a contract with Spain’s Ministry of the Interior to use the ship until October 5 at least and the deal might be extended if there are further security needs.
They said nobody intends to break the contract and the ship belongs to the Interior Ministry during the dates indicated.
Warner Bros then demanded that the characters were covered up.
So the Moby Dada has now re-appeared with vast canvas tarpaulins covering the Warner Bros characters.
But not before cartoon bird Tweety Pie was adopted as an ironic symbol of defiance by Catalan seperatists.
The Spanish authorities chartered cruise liners to accommodate more than 4,000 State Security Forces who have been drafted in it deal with any civil unrest in the regions.
Tensions are running high as Madrid pulls out all the stops to block a binding referendum on independence on October 1.
An unprecedented combination of legal action, police deployments and economic sanctions are disrupting the effort to hold the vote which has been declared illegal by Spain’s Constitutional Court.
Police have been sent to hunt down ballot papers and materials related to the referendum and media organisations have been warned not to broadcast official Catalan campaign advertisements related to the vote.
More than a hundred websites related to the referendum have already been shut down by the authorities.
National police forces from across Spain have been sent to Catalonia in anticipation of potential unrest in the streets.
They will be ordered to shut down polling stations if the Catalan regional police — the Mossos — are unable or unwilling to do so.
Madrid is in full crisis mode with Mr Rajoy expected to skip the European Union’s informal summit in Tallinn this week to concentrate on Catalonia.
And while ministers believe the infrastructure required to hold the referendum to has been “dismantled” few feel the crisis is near an end.
Hundreds of thousands of Catalans are expected to take to the streets on Sunday to try and cast a ballot.