Around 1,000 Border Force officers will strike at five airports over Christmas, PCS has announced.
The Home Office civil servants will take industrial action at London Heathrow, London Gatwick, Manchester, Birmingham, Cardiff and Glasgow airports on 23-26 and 28-31 December. Border Force staff at the port of Newhaven will also strike on the same dates.
The PCS union members involved in the action mainly conduct passport checks on people arriving into the country.
Around 100,000 PCS members in 214 government departments and other public bodies have voted to take strike action over pay, pensions justice, job security and redundancy terms.
The latest set of strikes follows action announced at the Driver and Vehicle Standard Agency, Rural Payment Agency, National Highways and Department for Work and Pensions.
The action announced so far is "part of a targeted and sustained programme industrial action that is designed to escalate each week, unless the government is prepared to put money on the table now to deal with the poverty of its own workforce", general secretary Mark Serwotka told a press conference yesterday.
"Our action is designed to get the government to see sense and give our members money to stop them using foodbanks.”
Serwotka said civil servants "are skipping meals and not being able to put the heating on a home because of the poverty level".
The government is planning to use members of the armed forces to replace striking officials, according to reports, which state military personnel have been receiving three to five days' training compared to the usual three to five weeks for Border Office staff.
Serwotka said it would be an “outrage” if armed forces replaced them with only three days' training.
Asked why the action was being planned over Christmas, Serwotka said his priority is “civil servants on poverty wages” and called the action a “last resort with the aim of getting the government to realise they can't do without the people they take for granted".
Around 40,000 civil servants are using foodbanks, according to PCS.
Serwotka also told CSW that the DWP strikes planned this month are only the "tip of the iceberg", with the union representing a further 40,000 people in the department who could go on strike. He said the union has so far announced action in only three job centres and one back-office as these staff are facing redundancy because the offices are closing.
A Home Office spokesperson said: “We are disappointed with the union’s decision to strike and the inconvenience this will cause to the public and businesses.
“We are working closely with all UK ports and airports to ensure we have robust plans in place to minimise any delays if strike action goes ahead, however passengers should be prepared for potential disruption.
“We will deploy suitable resource to meet critical demand and support the flow of passengers and goods through our border.
“We always recommend that passengers check the latest advice from their operators before travelling.”