Following the announcement of a four-day walkout by members of the Public and Commercial Services (PCS) union over 17-20 February, the government confirmed the effects would be felt at Dover, Calais and Dunkirk, as well as the Coquelles Channel Tunnel terminal.
The Home Office has advised passengers returning to the UK during the strike period to check the latest travel advice with their operators before travelling.
"Please be patient and respect officers who are working to keep the UK border safe and secure for all travellers during strike action," it added.
Military personnel, civil servants and volunteers from across government are being trained to support Border Force at airports and ports across the UK during the strikes. Passengers eligible to use eGates have been advised to do so.
On Wednesday (8 February), the PCS Union announced Border Force officials will stage a further 24-hour walkout on 15 March.
