PRIVATISATION would “brutalise” the National Gallery, a prolific artist warned yesterday as union stewards prepared to give notice for an unprecedented five days of strikes against the move.

Geraldine Swayne, whose work has been exhibited at the Barbican and the Saatchi Gallery, said plans to outsource visitor services and security jobs at the flagship London gallery would be a blow to workers and visitors alike.

Security firm CIS was drafted in to staff the gallery’s recent Rembrandt exhibition — and has been transferred to the gallery’s permanent exhibition since the show closed on January 18.

It is understood that the profiteer firm’s contract was extended, but the gallery has yet to put a contract out to tender for the permanent outsourcing of staff.

A union source close to the gallery — speaking anonymously following threats of disciplinary action to staff who talk to the press — said CIS was now running approximately one-third of the gallery’s rooms.

“They seemed to move seamlessly from the Rembrandt exhibition to other parts of the gallery, to keep their feet under the table,” the source said.

“There’s now a surplus of in-house staff but CIS are advertising again for new staff for the gallery. How are they finding the money for this?”

CIS advertisements have described stewarding the gallery as a “non-seated role” — despite the fact permanent staff are given chairs.

The source said CIS guards transferred elsewhere after the Rembrandt exhibition had been made to stand next to empty chairs in gallery rooms.

A demonstration against privatisation plans last week saw gallery attendants joined by anti-cuts activists, artists and art students.

Speaking exclusively to the Star yesterday, visual artist Ms Swayne said the gallery experience was being “parcelled off and sold to a stranger.”

She added: “These institutions are symbiotic with the art community in London, and a lot of art students and artists work there so they can survive.

“Everywhere is being sold off. Time and again you get private companies going into artistic spaces and brutalising them.

“To have galleries staffed by underpaid, non-unionised workers isn’t good for anyone.”

Strike dates will be announced later today.