Heathrow bosses said Terminal Five was “operating as normal” on Tuesday after huge queues built up at security on Monday because so many staff were told to self-isolate.
Passengers complained of “total chaos” after more than 100 staff were unable to work after being “pinged” by the NHS Test and Trace app.
A spokesperson for the airport said: “Monday we experienced some passenger congestion in Terminal Five departures, due to colleagues being instructed to self-isolate by NHS Test and Trace.
“We have activated additional team members to assist passengers with their journeys, and the operation has now returned to normal. We apologise to our passengers for any inconvenience caused.”
Meanwhile, hopes were growing that European destinations such as Italy, Germany and Bulgaria could this week join the Government’s green list of countries that do not require quarantine on return.
The next announcement is due on Thursday, with any changes coming into effect the following week, probably on Wednesday, July 21.
The Government has confirmed that from July 19 holidaymakers who have received two jabs will no longer be required to self-isolate for 10 days on their return to England from destinations on the amber list.