A UK Border Force spokesman said: "We flexibly deploy staff to meet demand, meaning that the vast majority of passengers pass through immigration controls quickly.
We will not compromise border security but work closely with airport operators to keep delays to a minimum."
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Poisoned double agent Sergei Skripal asked Vladimir Putin to be pardoned and requested he be allowed to visit Russia, according to a friend.
A cloudy and wet start on Saturday across many central and southern areas of the UK.
The White House said troops with a diagnosis of "gender dysphoria presents considerable risk to military effectiveness and lethality".