Heathrow said on Monday that passenger numbers tumbled nearly 83% in March as coronavirus restrictions continue to dent travel.
Passenger numbers fell 82.6% compared to the same month a year ago.
The government confirmed last week that summer holidays abroad from England can resume from 17 May at the earliest.
Transport Secretary Grant Shapps said Britons can “start to think” about booking foreign summer holidays, as the government outlined plans for a traffic light system to allow overseas leisure trips to resume. Shapps said it would be another two or three weeks before each country has been categorised.
Green countries will require only a privately-paid laboratory PCR test before travel at both ends, with no need for quarantine. However, red countries will require a 10-day quarantine in a designated quarantine hotel and all tests and quarantines will need to be booked and paid for prior to departure. The hotel quarantine cost will be £1,750.