UK immigration staff from the Public and Commercial Services union are due to be involved in a 24-hour strike from this evening (June 29th).
The industrial action is planned to start from 18:00 BST although times will vary depending on the different shift patterns of each organisation taking part.
While people using overseas UK visa services are unlikely to be affected, premium service applications for UK visas from within the country may be held up as certain members of staff from the UK Border Agency are taking part in the strikes.
Delays at border control are also to be expected, although contingency plans are in place to attempt to reduce the hold up. To keep the system moving as swiftly as possible, people coming to the UK are requested to have their travel documents at hand.
A shop steward with the union suggested that UK immigration control could be compromised. Sue Kendal remarked: "It takes an experienced immigration officer to be capable of detecting a forged passport. I think passport control will be extremely vulnerable."
Anybody who is able to travel on an alternative day has been advised by UK immigration officials to do so in order to avoid delays and queues.