By Natalie Thomas and Kate Holton
LONDON (Reuters) - Ryanair boss Michael O'Leary said he believed Britain's coronavirus quarantine will be struck down by the courts or dropped within weeks as some of Europe's biggest airlines prepare to file a legal challenge by the end of Tuesday.
The 14-day quarantine for international arrivals, introduced on Monday, has led to the most vociferous clash between a major industry and Prime Minister Boris Johnson's government during the COVID-19 crisis.
By insisting on the quarantine despite public pleas from airline veterans such as IAG's Willie Walsh and O'Leary, Britain has united some of the fiercest rivals in aviation who are already reeling from a sudden global halt in air travel.
O'Leary said he hoped a court would hear an emergency legal challenge by the end of this week to halt the quarantine - imposed just as most European countries were reopening their economies.
"I think in their heart of hearts, the government would like the courts to strike it down because it would get them off the hook," the Ryanair chief told Reuters TV. "I think either the courts will strike it down this week or the government will quietly drop it before the end of June."
The legal action, proposed by British Airways (L:ICAG) and supported by low-cost rivals Ryanair (I:RYA) and easyJet (L:EZJ), is seeking injunctive relief and legal papers are due to be filed on Monday or Tuesday, he added.
Lawyer Tom Snelling, at Signature Litigation, said the government would have to show the measure was anchored in scientific evidence and not politics.
Slow to introduce lockdown measures and with one of the highest death tolls in the world, at more than 50,000, Britain argues a quarantine is needed to prevent a second surge of COVID-19.
The government did not respond to O'Leary's remarks.
'RUSHED THROUGH'
The quarantine imposes fines of up to 1,000 pounds ($1,270) for any breaches.
The three airlines believe the measure is ineffective as passengers can still board public transport on leaving an airport, and it is hard to enforce.
Walsh, the head of BA-owner IAG, told LBC Radio they would argue the legislation was irrational, while easyJet boss Johan Lundgren said it had been rushed through.
"It's not in proportion," Lundgren told Sky News.
The quarantine will be reviewed every three weeks, the government says. It is also looking at "air bridges" that allow tourists to travel between two countries without needing to quarantine.
"It wouldn't be that surprising if we're looking actually at a slightly different type of measure fairly soon, possibly even within the first three-week review cycle,” Snelling said.
O'Leary said Britons were booking outbound flights for holidays despite the quarantine, but Europeans were not coming to Britain.