A major union has criticised No 10 for not offering civil servants the lump sum cost of living payments that other public sector workers such as teachers and health staff have been promised. Prospect union’s general secretary, Mike Clancy, said as members prepared to strike that the unions had been “given every indication” that the pay offer for civil servants would follow the same template as others in the public sector. Teachers, rail workers and health staff have all been offered one-off lump sums to help deal with cost of living pressures. However, Clancy said this idea appeared to have been “abruptly” dropped when the Cabinet Office put a pay offer on the table last month. All civil servants were instead offered just 4.5% in 2023/24 for most officials at a time when inflation is in double digits, following 2-3% the previous year. “We speculate this was a decision at No 10 communicated to the Cabinet Office and it beggars belief because you can’t come up with a logical reason for doing this,” Clancy said. “We are not going to let go of the fact there was every indication that more was available but civil servants in the end were treated worse than everyone else. Why? Someone needs to answer this question and explain.” Although a lump sum was never formally offered to the civil service unions, several sources said it was generally understood that a cash payment would be forthcoming. But when Jeremy Quin, a Cabinet Office minister, presented the pay offer, he appeared embarrassed that it did not match up to the deals put forward for other public sector workers. Prospect members are now set to strike on Wednesday, after a previous day of action on 15 March and continuous rolling industrial action of working to rule and an overtime ban since then. It is the largest industrial action taken by the union in more than a decade, covering specialist, technical, professional, managerial and scientific staff in Whitehall agencies such as the Met Office, Health and Safety Executive and Natural England. It adds to other strikes among civil servants in the PCS union, whose 130,000 members have staged repeated industrial action for months. The union is now re-balloting for further strike action. Some of its members in HMRC are also set to strike on Wednesday and further days this month and in June. Mark Serwotka, the PCS general secretary, said: “Our members in HMRC are the latest in a long line of PCS members being forced to take strike action to fight for the pay rise PCS members deserve. “In HMRC alone, almost one in three staff are now on national minimum wage. In DWP one in five staff are having to claim in-work benefits. These people are the government’s own workforce, who are suffering the consequence of year after consecutive year of meagre pay rises leaving tens of thousands of them in financial crisis. “We will not accept being left behind. We will not accept being treated like the poor relation. PCS members are determined to keep the pressure on until the government improves its offer to us.”