Immigration staff at UK airports have today staged a walk-out.
The strike started at 00.01 and will last until midnight tonight.
Airports are currently operating normally, albeit with a reduced passenger flow after a number of airlines took the decision to cancel flights, into Heathrow especially.
Queues at Heathrow Airport, which asked airlines to halve the number of passengers they flew into the airport, seem to be at a minumum.
One of the latest updates on Twitter for Heathrow, by Virgin Atlantic, said: “Non-EU Passport queue at LHR T3 appears to be manageable right now. Same for the 'Trusted Nations' queue.”
Gatwick Airport is also using Twitter to communicate updates. Its latest post said: “Currently we have no delays and all flights are being processed through passport control as normal.”
Stewart Wingate, Gatwick's CEO, said: “We have just got through our first busy peak with no disruption to the inbound flights and no knock-on effect to the outbound flights.
"Arriving passengers have been processed safely through passport control as normal with no delays."