Strike action will be taken by Border Force staff at airports in England, Scotland and Wales over Christmas.
It impacts PCS members working at passport control at London Heathrow, London Gatwick, Manchester, Birmingham, Cardiff and Glasgow airports on 23, 24, 25, 26, 28, 29, 30 and 31 December 2022.
Around 1,000 staff are expected to walk out on these days.
PCS general secretary Mark Serwotka said: “The government can stop these strikes tomorrow if it puts money on the table.
“We will fight to improve our members’ pay, terms and conditions, regardless of who is in Downing Street.”
Border Force officers are employed by the Home Office.
A Heathrow spokesperson said: “Our priority is to ensure passengers get through the border safely and as quickly as possible. We are working closely with airlines and Border Force on mitigation plans for potential strike action by Border Force officers and these plans will now be implemented for the notified days.
“The Home Office advises that immigration and customs checks may take longer during peak times on strike days, and Heathrow will support Border Force to minimise these impacts with the aim of processing passengers through the border as efficiently as possible.
“Passengers are advised to check their flight status with their airline before travelling. We encourage all parties to resolve this dispute quickly.”
This announcement comes after a Which? Travel survey revealed that security queues were causing passengers to miss flights before strike action.