Staff working in passport control at Heathrow Airport in London will go on strike over Easter.
The week-long strike is due to start on April 1, three days before Easter Sunday.
The PCS union said the dispute was over the imposition of new rosters, which it considers unworkable.
Travellers faced waiting in queues for more than seven hours to have their passports checked in recent weeks, which the union blamed on the rosters.
"If a system causes people to stand in a queue for seven hours at passport control, the system is flawed. We would urge Border Force to do the right thing by passengers and our members, and agree with our reasonable proposals,” PCS general secretary Mark Serwotka said.
Almost 450 workers are involved in the strike.
“The Home Office has claimed it imposed rosters in response to Covid safety measures but many staff have reported they feel less safe than with the previous roster," the union said.
“The Home Office Border Force has refused to agree to reasonable demands that would see an end to this untenable situation.”
The strike action follows a ballot vote in January, in which 96.4 per cent of those who voted said yes to strike action, on a 68 per cent turnout.
Unite members also plan to walk out after they announced yesterday they would be striking over Heathrow Airport's decision to fire and rehire its entire workforce on different conditions.