Travellers are being warned to prepare for lengthy delays due to border force strike action as half-term comes to an end.

The force has announced walkouts for four days starting tomorrow – when many families will be returning home from holidays.

The strikes, which have been planned by Public and Commercial Services Union, are set to affect both ferries and the Eurotunnel coming into Kent.

Action is due to take place at the Port of Dover, as well as the ports of Calais and Dunkirk on the other side of the Channel.

The Eurotunnel terminal in Coquelles, France, is also set to be affected by the walkouts.

A statement from the Home Office says military personnel have been trained to stand in for striking workers.

"Hundreds of people from across government and the military have been trained to carry out essential checks at the border," added a spokesperson.

"They will be present at airports and ports across the UK, not only at the locations directly impacted by strikes."

However, anyone hoping to travel back today and over the weekend has been warned to prepare for longer delays on both sides of the channel.

The warning lasts from tomorrow morning until around 7am on Monday morning, when normal service is expected to resume.

Steve Dann, Border Force chief operating officer, said: "It is disappointing for travellers that yet again strike action may cause disruption for those entering the UK.

"Border Force’s number one priority to is keep our citizens safe and borders secure. We are working together with partners across the travel industry and our French counterparts to ensure we can continue to meet critical demand and support the flow of passengers and goods through our border.

"During the periods of industrial action, travellers should be prepared for disruption. We encourage everyone to check the latest advice from operators before travelling.