"It is cynical of the gallery to try to press ahead with this sell-off in the run-up to the general election and before the new director has taken over," said PCS general secretary Mark Serwotka.
"The process should be halted now and we should be given a proper chance to discuss maintaining services in-house."
The National Gallery -- which is the world's fourth most-visited museum and home to masterpieces by JMW Turner, Vincent van Gogh and Leonardo da Vinci -- said that public access to some areas would be limited from April 20 to 24 as a result of the strike.
Staff have already walked out for 17 days in protest at the plan, which the gallery says mirrors changes that have already taken place in most major British museums.
In a statement, a gallery spokesman defended the plan to appoint an external partner to manage visitor-facing and security staff, saying it would allow the gallery to operate more flexibly and would not result in job cuts.
"The National Gallery is a public asset and has a duty to ensure the collection and the gallery itself is accessible as much as possible to as many people as possible," the spokesman said.
"We believe the proposed changes are essential to enable us to deliver an enhanced service to our six million annual visitors for many years to come, and to remain as one of the world's leading art galleries."
-----------------------------------------------------------------------------------------------------------
"The process should be halted now and we should be given a proper chance to discuss maintaining services in-house."
The National Gallery -- which is the world's fourth most-visited museum and home to masterpieces by JMW Turner, Vincent van Gogh and Leonardo da Vinci -- said that public access to some areas would be limited from April 20 to 24 as a result of the strike.
Staff have already walked out for 17 days in protest at the plan, which the gallery says mirrors changes that have already taken place in most major British museums.
In a statement, a gallery spokesman defended the plan to appoint an external partner to manage visitor-facing and security staff, saying it would allow the gallery to operate more flexibly and would not result in job cuts.
"The National Gallery is a public asset and has a duty to ensure the collection and the gallery itself is accessible as much as possible to as many people as possible," the spokesman said.
"We believe the proposed changes are essential to enable us to deliver an enhanced service to our six million annual visitors for many years to come, and to remain as one of the world's leading art galleries."
-----------------------------------------------------------------------------------------------------------