Border Force members of the Public and Commercial Services union staffing passport control will walk out over 23-26 December and again over 28-31 December, the union confirmed last week.

The action will take place at Birmingham, Cardiff, Gatwick, Glasgow, Heathrow and Manchester airports, as well as Newhaven’s passenger ferry port. While Heathrow has this week played down the likely impact of the strikes, Manchester airport has said some cancellations are likely.

Government says its number one priority will be to keep the country’s borders "safe and secure" for all passengers, warning it will not compromise on safety during the strike period.

Military personnel, civil servants and volunteers from across government are currently being trained to support Border Force at airports and ports across the UK.

Nonetheless, the Home Office has warned delays processing arrivals are likely, and has urged anyone with a biometric passports to use eGates when transiting the UK border.

"Border Force and the travel industry work together very closely at a local and national level and have regular meetings to agree plans for pressures while keeping the public safe," said the Home Office.

"Border Force are ready to deploy resource to meet critical demand and support flow travellers through the border, however those entering the UK should be prepared for potential disruption.

"We continue to work closely with port operators and airlines to minimise disruption and delays at the border during any industrial action."

The Home Office has issued advice for passengers, travel agents, tour operators and the wider travel industry to be aware of in the lead up to the strike period, and during the strikes.

Passengers

• Those who are due to travel into the UK during the proposed industrial action should be prepared to face longer wait times at UK border control;
• All passengers should check the latest advice from their travel agents, tour operators and/or airlines or carriers before travelling to check if the proposed strike action will affect their journeys;
• Passengers are reminded to be patient and respect officers who are working to keep people safe and the border secure, and supporting travellers during the strike action;
• All passengers eligible to use eGates are encouraged to do so;
• Abuse and inappropriate behaviour will be reported to the UK police

Flights

• The Home Office says it is working with operators and ports to understand the impact of industrial action on inbound flights;
• Passengers travelling into the UK during strikes should check with their airlines for the latest travel information and advice before travelling;
• There are often a few things that might influence border control wait times, including an increase in passenger numbers, flights delays and flight bunching, as well as weather an "other ad hoc incidents"

Wait times

• The Home Office has warned accurate queue time data can take time to gather and check, advising anyone travelling during the proposed strike dates to be prepared for longer wait times;
• Passengers can check airport websites before travelling to stay up to date with the latest information related to travel or possible delays caused by strike action