More than 2,000 civil servants working for the Public and Commercial Services (PCS) union decided to take further action in a long-running dispute over pay, jobs, pensions and conditions.
British Museum staff will take seven days of strike action over the Easter holidays (April 6-12) while British Library staff will take 14 days action from April 3-16.
The move will deal a blow to the thousands of tourists hoping to visit the museum over the holiday period. The 250-year-old institution draws more than six million visitors annually, making it among the most popular cultural attractions in the UK.
The museum was hit by strike action last month, when more than 100 staff members staged a walkout, resulting in the cancellation of half-term activities and the disruption of many services, including the closure of the ticket and box office and information desk.
The PCS says it is stepping up pressure on the government to resolve the row.
National Highways workers will also walk out from April 3-7 and driving examiners employed by the Driver and Vehicle Standards Agency (DVSA) will take regional rolling action from April 5-28.
Border Force officers and immigration staff in Belfast will also be taking action on April 12-14.
The announcement follows last Wednesday’s strike by 133,000 civil servants and comes after Friday’s news of a five-week strike by workers in the Passport Office.
PCS general secretary Mark Serwotka said: “Ministers have had meetings with other unions but, in six months, have had no meaningful talks with us. Our members are fed up with being at the back of the queue.
“Because of inflation and the cost-of-living crisis, their pay has effectively gone backwards during this time, so it’s no wonder they’re taking more strike action.
“I can warn ministers that even more strikes will follow unless they engage with us and put money on the table.
“I’m often asked if our members can afford to strike. At this moment in time the answer is simple: they can’t afford not to.”