EasyJet said it was poised to ramp up summer flight schedules with an easing of Covid-19 restrictions.
But the UK low-cost airline warned that the late announcement of travel rules reduced visibility as it reported a wider half-year loss.
EasyJet expects to operate about 15% of pre-crisis capacity in the current April-June quarter, it said today, before returning furloughed crews for a much-anticipated summer surge.
"We have the ability to flex up quickly to operate 90% of our current fleet over the peak summer period to match demand," chief executive Johan Lundgren said in the airline's results statement.
As the peak season approaches, travel firms are pushing governments to drop quarantines and other curbs for vaccinated passengers and lower-risk destinations.
Britain's "green list" of unrestricted countries is up for review in coming weeks, but the government has warned that the highly contagious coronavirus variant first detected in India may yet slow the pace of reopening.
EasyJet's said its pre-tax loss widened to £701m in the six months ending March 31, from £193min the year-earlier period affected only partially by the pandemic.
Revenue fell 90% to £240m on a similarly sharp decline in passenger numbers to 4.1 million.
Underlining the summer doubts, the airline gave no firm capacity plan for its July-September fourth quarter.
"Given the continued level of short-term uncertainty it would not be appropriate to provide any further financial guidance," it said. The carrier said its cost-cutting programme was on track to save £500m this year.
Conditions are nonetheless ripe for a strong summer rebound and EasyJet said it increased capacity by more than 105,000 seats after publication of the UK green list – which triggered a UK-Portugal bookings spike.
"We know there is pent-up demand," CEO Lundgren said.