The Basque government has requested that the painting be moved to the Guggenheim Museum in Bilbao to mark the 90th anniversary of the bombing of the Basque city.
The anti-war painting has been hanging in Madrid's Reina Sofía museum since 1992, and repeated requests to move it to the Basque Country have been rejected. The latest request has led to insults between regional representatives - with both sides calling each other "provincialists".
"Guernica" is a memorial to the small Basque town of the same name, which was completely destroyed in 1937 by the air forces of Nazi Germany and Italy, with the approval of Spanish fascist leader Francisco Franco.
