At least 100,000 civil servants will join one-day strike action on budget day in a significant escalation in a long-running dispute over pay, pension and job security demands. The strike by the Public and Commercial Services (PCS) Union, which will comprise workers from across 123 government departments, is scheduled to coincide with Jeremy Hunt’s announcement of his first full budget on 15 March, as the government prepares to wrest control over the cost of living crisis and stick to its deficit reduction plan. It comes after tens of thousands of union members joined industrial action from PCS members 1 February, which forced the army to be called in to replace striking border officers, and the British Museum to shut. PCS members are suffering an “unacceptable” pay decline, said the union’s general secretary, Mark Serwotka, citing the 40,000 civil servants who have used food banks and a third of HMRC staff who will be earning just above minimum wage by April. “It’s an appalling way for the government to treat its own workforce,” Serwotka said. “Rishi Sunak doesn’t seem to understand that the more he ignores our members’ demands for a pay rise to get them through the cost-of-living crisis, the more angry and more determined he makes them.” Echoing previous warnings, Serwotka said the prime minister could end the dispute immediately by putting “more money on the table” – threatening that should he choose not to, “more action is inevitable”. Industrial action from PCS members is set to continue throughout February. However, should PCS members in HMRC, Care Quality Commission, Companies House, National Museum of Wales and others ballot to join the upcoming strike action, a further 30,000 workers will join the 100,000 already poised to strike. Unions and the government appear as far apart as ever after striking workers from participating unions held rallies in cities including Bristol, Brighton, Birmingham and London last week. Teachers, university staff, rail workers and civil servants have all stopped work to demand better pay. Prospect union said they are currently balloting public sector employees on industrial action, which closes on 24 February. While the possible strike dates are to be decided, a spokesperson said: “It is not out of the question it would be the same day.”