A row has broken out between the Madrid and Basque regional governments in Spain over the latter’s request for Guernica, probably Picasso’s most celebrated work, to be housed temporarily in the Guggenheim Museum in Bilbao to mark the 90th anniversary of the bombing of the Basque town.

The work has hung in the Reina Sofía museum in Madrid since 1992 and repeated requests for it to be moved to the Basque Country have been refused.

The latest request has seen Isabel Díaz Ayuso, Madrid’s outspoken, conservative president and Aitor Esteban, leader of the Basque nationalist party, trade insults, each accusing the other of being “provincial”.

“It makes no sense for everything to be returned to its origin,” Ayuso said. “In that case we should send all of Picasso’s works to Málaga,” referring to the city where he was born.

“It represents a provincial mindset when culture is universal,” she said, adding the Reina Sofía insisted moving Guernica risks damaging the work.

Esteban retorted that if anyone was provincial, it was Ayuso whose idea of national identity “is to drink beer on the terrace of a bar”, a reference to the Madrid president’s insistence on keeping bars open during the pandemic.

Imanol Pradales, the Basque president, asked, “Does the Spanish government have the courage to move Guernica? They dragged Franco out of his tomb and aren’t capable of moving a painting from Madrid to Euskadi [the Basque region]? The ball is in their court.”

The Basque government wants the painting to be hung in the Guggenheim from 1 October until 30 June to commemorate the 90th anniversary of the bombing of Guernica.

Picasso’s black-and-white masterpiece depicts the violence of the attack carried out by the Italian air force on April 26, 1937, during the Spanish civil war. Italy was an ally of the Spanish general Francisco Franco and the attack was an early experiment in what would soon become a commonplace of warfare: the aerial bombardment of civilians.

Estimates of the number killed in Guernica vary widely, from 126 to 1,654, but in any case Picasso’s work became an international symbol of the horrors of war.

He painted it shortly after the event and it was exhibited at the Paris International Exposition in 1937. After that it toured Europe and the US and, as Picasso opposed its return to Spain during the Franco dictatorship, for many years it was hung in the Museum of Modern Art (MoMA) in New York.

In 2000, the Reina Sofía turned down a request from MoMA to borrow Guernica, saying “the great icon of our museum must remain, without exception, separate from the policy on lending works to other museums”.