Britain’s surprise move to quarantine passengers arriving from Spain dealt a heavy blow to European airlines already reeling from the coronavirus crisis – and sowed new doubts about the prospects for a steady travel recovery. Airlines slammed what they characterized as a disproportionate decision, as their shares sank across the board amid fading hopes that an improvement in traffic could yet allow them to salvage part of the critical summer season. EasyJet shares were down 7.7% at 1500 GMT, with British Airways parent IAG lost 6.1%, Lufthansa <LHAG.DE> 5.3%, Air France-KLM 5% and Ryanair 4%. Ryanair Group Chief Executive Michael O’Leary called the UK measures “a badly managed over-reaction” as he unveiled a 185 million euro ($217 million) quarterly loss along with a more downbeat recovery outlook. While there was “no scientific basis for a national restriction”, O’Leary said he expected to see more COVID-19 “spikes and occasional restrictions continuing throughout the summer and into the winter period”. Britain does not rule out restoring quarantine for arrivals from other countries such as France and Germany, where it is monitoring infection rates, a junior minister said. The British measures follow new travel curbs or negative advice from countries such as Norway and France, after an uptick in infections in Catalonia and some other parts of Spain. The British steps are more draconian as well as more consequential, with UK-Spain flights accounting for 17% of intra-European summer capacity, according to OAG data.