Saura and Querejeta plan Picasso 'Guernica' film

It all happened in an old atelier at No. 7, Rue de Grands Augustins, Paris. And it all happened in 33 days- the time it took Pablo Picasso to paint Guernica, today one of the most important works in art history. He had initially received the Republican delegation's commission to paint a mural for the Spanish Pavilion of the Paris World Exhibition somewhat reluctantly. But the indiscriminate bombing of the town of Gernika by Franco's Condor Legion on April 26, 1937 changed his opinion. He started painting frenetically. And his lover Dora Maar began to photograph the process.

This is the story to be told in 33 días (or, 33 days), the new film by director Carlos Saura, based on an original idea by Elías Querejeta and likely starring Franco-Spanish actor José García as the Malagueño artist. It is a fascinating subject for a historic reencounter between two Spanish filmmakers who haven't worked together since Dulces horas 30 years ago. Before that, Saura and Querejeta were responsible for bringing several classics of Spanish cinema to the screen, including La caza, Peppermint Frappé and Raise Ravens.

Both he and Querejeta are currently immersed in a sea of arguments over the script. "Elías always insists on arguing, even though the truth is I already have this film very clearly in my head," says Saura, amid laughter.

"Fuck, it seems like we are doing La caza all over again!" shouts Querejeta in the middle of the downtown Madrid bar where we are talking. The Basque producer put the project into motion more than a year ago, but will not produce it himself owing to the legal process in which he finds himself embroiled following the winding-up of his production company.

Set to begin filming in Paris and Gernika in June, 33 días will tell the story of the painting, but also the story about the mad love Picasso shared with his young wife Marie-Thérèse Walter and his faithful lover, the photographer Dora Maar. The former would visit him in his studio in the mornings; the latter in the afternoons. That was until one day, a timetabling mistake led to an unexpected meeting - which is where the script reaches its climax.

"I want to recreate Picasso's personal world around Guernica, like the fact that painting this picture was almost a salvation for him at a moment of personal crisis," says Saura. "And above all I want to portray his relationship with Dora Maar, a fascinating character who has interested me my whole life."

The filmmaker admits to being obsessed with the subject matter: "I've been researching without a break since October, surrounded by books on all sides... the truth is, I am almost up to my eyeballs in Picasso, a character I adore, as my [artist] brother Antonio also did."