The professionals’ union has described the two-year deal as “insulting” as it only sets aside 1.5% for a cost of living increase in 2007, with nothing at all except performance-related pay increases allocated for 2008. It even falls below the spending levels set by the Treasury.

The action taken by curators, conservators, specialists, managers and explainers at NMSI will cause disruption to services at the Science Museum in London, the National Rail Museum, York, the National Media Museum, Bradford, and the Science Museum, Swindon.

Members will demonstrate outside the main entrances of the museums from 9am onwards. They will be joined by colleagues from their sister union PCS.

Tomorrow’s strike follows lengthy negotiations with NMSI management and an agreement to stay planned industrial action in February. But with no successful resolution of the dispute, Prospect National Secretary Emily Boase said: “Members are furious and their patience has been exhausted.”