Croatia faces being removed from the UK’s travel corridor list, with imported Covid-19 infections from the country having been identified, the Guardian understands. Ministers are likely to remove the country from the list after logging a recent surge in coronavirus cases. If the measures are formally signed off, it would mean people arriving from Croatia will have to quarantine for 14 days in Britain. The transport secretary, Grant Shapps, met ministers on Wednesday afternoon to discuss plans. An announcement could come as early as Thursday. If Croatia is removed the change could affect thousands of British holidaymakers in the country at the moment. The Guardian has been told that officials at the government’s Joint Biosecurity Centre have flagged specific coronavirus cases imported to the UK from Croatia. It is not known how many cases have been identified or where in the country, but it is understood that the number of imported cases is at a similar level to that shown by Spain when it was removed from the travel corridor last month with just a few hours’ notice, prompting chaos for holidaymakers. However, when France and five other locations were removed from the travel corridor list last week ministers allowed 30 hours’ notice before the measures were imposed on arrivals to the UK, from Saturday at 4am. It is likely that any move to remove Croatia could come with a similar notice period. On Tuesday, Croatia reported 199 new Covid cases. As of Wednesday, according to the European Centre for Disease Control, the 14-day cumulative number of Covid-19 cases in Croatia was 37.7 per 100,000 people, compared to the UK’s 21. According to the aviation data analysts Cirium, from Wednesday until the end of September there are 767 flights run by large airlines scheduled to fly from the UK to Croatia, with a total seat capacity of nearly 130,000. Paul Charles, the CEO of the travel consultancy PC Agency, which has been monitoring travel corridor developments and estimates there are 20,000 British holidaymakers in Croatia at the moment, said he believed Croatia would be removed “based on the government’s own criteria”. But he said he thought Croatia would be the only country affected by such changes this week. Portugal, which ministers last week agreed to monitor after infection rates improved there, is under consideration to be added to the quarantine exemption list. Locations understood to be under close watch amid rising infections are Greece, Denmark, the Faroe Islands, Austria, Switzerland and Gibraltar. Individual decisions on whether or not to remove destinations from the travel corridor are taken by devolved administrations, but last week’s removal of France from the list was taken in unison by the four UK nations. The Department for Transport has been approached for comment. The aviation industry has been lobbying for the UK government to agree to use airport testing to reduce the 14-day quarantine period. Under the proposals passengers would take a test on arrival at airports, then a second test several days later with a view to being allowed to break their quarantine early if each test returned negative results. Heathrow unveiled a multi-million pound testing facility this week which awaits the go-ahead from ministers. The government has resisted use of the facility to date. Asked on Wednesday whether the government would bring in airport testing to reduce quarantine times, the health secretary, Matt Hancock, said: “We’re working on that.” This article was amended on 20 August 2020. The original incorrectly spelled the aviation data analysts Cirium, as Cirum. This has been corrected.