The ongoing dispute between London’s National Gallery and the museum’s staff has culminated in the announcement of an indefinite strike as workers continue to protest against privatization.

On Monday, the Public and Commercial Services (PCS) union said that about 200 members would begin the walkout on Tuesday, the BBC reported. The PCS has already staged 56 days of strikes since February, including a 10-day walkout in May.

According to AFP, museum director Gabriele Finaldi announced in late July that the institution had signed a five-year deal with contractor Securitas to take over security and front-desk services.

The National Gallery insists that the privatization of about 400 visitor service jobs is essential.

Deputy director Susan Foister said “We need more flexibility to offer better service to our visitors, we have nearly 6.5 million visitors a year and we want to offer more access, better access and events and activities to as many people as possible.”

In a radio interview with the BBC, PCS representative Nick McCarthy countered that “We have no alternative but to go on strike, the privatization is completely unnecessary. Today’s strike is indefinite until such time as we are able to reach a solution with the gallery.”

He added “Millions of tourists won’t be able to get access to the vast majority of works of art in the gallery, and that’s enormously regrettable, but the blame for this lies with the gallery. We have sought to negotiate, but the gallery refuses to engage on this and seems hell bent on outsourcing this contract.”

Although the museum will remain open during the strike, several rooms will be closed and many educational programs have been canceled.

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