Prospect, the union for professionals, has stepped up its campaign against mooted cuts to the Imperial War Museum (IWM) library, launching a poster campaign on the London Underground.
The posters urge people to sign a petition against the closures, which has already attracted more than 18,000 signatures so far.
Last November, the museum announced that it was consulting on a restructure for the organisation, which could see its library closed to the public and up to 80 people lose their jobs. The potential cuts follow a projected £4m annual deficit, as a result of the government grant-in-aid shrinking.
Andy Bye, Prospect negotiator, said: "The museum’s vision to promote the understanding of both the causes and consequences of conflict cannot be fulfilled if the library is closed. It’s a simple as that. More than 18,000 petition signatures collected in just a few months show the public agree."
Prospect has also warned that, should the closures go ahead: "IWM will no longer be able to meet the requirements of the Arts Council accreditation scheme for UK national museums. These stipulate the provision of study and research facilities for academic and public use."
In a submission to the IWM's consultation, Prospect suggests that the institution should make greater use of visitor donations and raise money through means such as tours, workshops and courses. Money recently donated by the government, earmarked for IWM Dixford, HMS Belfast and the Churchill War Rooms, part of the IWM network, should also have been distributed to the library, it argues.
Bye said: "It is vital that visitors are encouraged to donate as much as possible in the current financial climate and other museums and galleries have made much greater effort in this regard. These efforts have yielded positive results and show that cost saving plans put forward by IWM’s management are ill thought out and short-sighted."
IWM did not respond to requests for comment.