Staff at the National Gallery in London began a five-day strike on Tuesday in protest against what trade unions say is creeping privatisation of the popular tourist attraction.
Most of the museum was forced to shut down because of the protest and a small group of around 40 people rallied outside the museum holding up placards and shouting: "Privatisation, no way!"
"Due to industrial action by some members of the staff, there are substantial room closures today," read a statement on the entrance to the museum.
The protest organised by the Public and Commercial Services Union is against the hiring of an external partner, a private company called CIS, to manage a new staff roster for extended opening hours.
"The gallery wants to privatise 400 of the 600 staff here and our experience of privatisation is that it doesn't improve the service, it actually makes it worse," said Paul Bemrose, PCS national officer.
But the museum said it needs the changes to increase revenues because state subsidies are being cut and costs are growing.
As he was leaving the museum, Peter Coltman, a visitor, said he was disappointed that parts of it were closed but was supportive of the strike.
"It's about time that people in this country actually stand up and say we've had enough," he said.
Situated on Trafalgar Square, the National Gallery is free to enter and is one of the world's most popular art museums with around six million visitors a year.
