A Border Force spokeswoman said: "We will not compromise border security, but we always aim to keep disruption to a minimum by using our staff flexibly to meet demand.
"Carrying out full checks at airports help us stop threats from terrorists, criminals and others who want to harm the UK, and make sure that only those with the right to enter the UK can do so."
More top news
Billionaire Microsoft co-founder Paul Allen has claimed discovery of the Japanese battleship Musashi that was sunk by the US Navy in 1945.
Friday will be mostly dry with sunny spells for much of the UK. Temperatures will be mild across the country.
Some famous Liberal Democrat names will be fighting for their political lives in the election, now just over two months away.