STAFF at the National Gallery will launch a 10-day strike tomorrow against the privatisation of their jobs.

It is only the latest action in a long-running campaign by members of Civil Service union PCS that has so far involved 24 days of strikes since February.

Management escalated the dispute when it suspended, then sacked, union representative Candy Udwin before the first strike.

Labour MP John McDonnell plans to raise her dismissal and the privatisation of the jobs in the Commons.

“This privatisation plan is totally unnecessary and is damaging the well-earned reputation of the gallery,” said PCS general secretary Mark Serwotka.

“The sacking of our representative, Candy, is a disgraceful attack on our union.”

This week’s strike will hit school half-term holidays, when visitor numbers increase, and will be the longest of the campaign.

The National Gallery conceded that the strike would affect visits, but said that it hoped to keep open as much of the gallery as possible.

It will again ratchet up the dispute by appointing an “external partner” to take over the jobs done by the strikers.

A rally will be held in Trafalgar Square, outside the National Gallery, on May 30.

“Our demonstration is not just about this sell-off and the victimisation of Candy, it is an opportunity to oppose the kind of Tory cuts being cited as a rationale to hive off staff to the private sector,” said Mr Serwotka.

Gallery management at the wants to privatise up to 400 of 600 jobs, including those who look after security of the paintings, deal with the public and requests for information about the collection, complaints, school bookings and more.

Organised group visits to the gallery involving thousands have been cancelled because of industrial action.

Organisations backing the strike include the People’s Assembly, Musicians’ Union and broadcasting union Bectu.

The gallery has refused to make a statement about the sacking of union rep Candy Udwin, saying it does not comment on individual disciplinary cases.