The government's U-turn on screening passengers for Ebola at UK airports threw operators into chaos on Friday morning, with one airport admitting it had no idea how to implement the measures.
Airport screenings have been criticised by health experts, who said the project would come at vast expense and not help prevent the disease from spreading beyond west Africa.
The confusion came as it emerged a British man who was initially suspected to have died from Ebola in Macedonia was declared "unlikely" to have been suffering from the virus.
Experts also warned cases of Ebola in Britain were ‘bound to happen,’ but that screening would do little to identify infected passengers.
Border Force check the passports of passengers arriving at Gatwick Airport
Checks will now take place at Heathrow, Gatwick and Eurostar terminals following advice from chief medical officer Professor Dame Sally Davies, amid growing criticism of the Government for delays in responding to the outbreak.
But a spokesman for Gatwick, The UK's second busiest airport, said today that it had not been given any instructions about how the screening should be carried out.
"We've not had anything at all," he said. "We're still waiting for Public Health England (to let us know)."
A spokesman for Heathrow said the airport was working to implement the reactive measures. He said: "We would like to reassure passengers that the Government assesses the risk of a traveller contracting Ebola to be low. The welfare of our passengers and colleagues is always our main priority and we are working with Government to support the implementation of the additional screening measures."
The Government appeared not to know exactly what its policy was, with different messages coming from different departments. Chancellor George Osborne said screening would be introduced if medical experts deemed it necessary. Then, the Department of Health initially insisted it had no plans for screening. Then, Defence Secretary Michael Fallon said existing Government policy was in line with WHO advice that exit screening was more effective. Then, the Government announced it would begin screening.
David Mabey, professor of communicable diseases at the London School of Hygiene and Tropical Medicine, said the screening was a "complete waste of time".
"Firstly, there won't be anyone coming from these (west African) countries because all direct flights have been cancelled," he said. "Are they going to screen everyone from Brussels, Paris, Frankfurt and Amsterdam? That would lead to a lot of delays and disruption.
"Secondly, why would anyone admit that they have been in contact with someone when they're in a hurry to get through immigration control when they arrive at the airport?
"People will have been screened before getting on flights and may seem to be healthy if they're not yet showing symptoms.
"And then what will they do if they think they do have Ebola? Lock them up in solitary confinement?"
Prof Mabey said that instead, the Government should be concentrating on increasing awareness of what people should do if they think they might be at risk.
Asked if he thought there would be cases of Ebola in the UK, he said: "I think it's bound to happen. We have a lot of links with west Africa. There is lots of coming and going so I'm sure there will be a few cases."
World Health Organisation director of strategy Dr Chris Dye said it was unlikely the screening would detect anyone with Ebola coming into the UK.
"The chances of someone with Ebola turning up in the UK is relatively small," he told BBC Radio 4's Today programme. "The chance of someone turning up in the UK showing symptoms of Ebola at the time is even smaller.
"It potentially could prevent a few cases but I suspect the more important impact is that it will hugely increase awareness."
Conservative MP Rory Stewart also criticised the plans, saying it does not make sense to carry out tests only at certain airports or railway stations. He told Channel 4 News: "If we're moving into a situation in which we're seriously screening for an epidemic, then we need to get it right across all ports of entry. It doesn't make sense to only screen limited places."
Downing Street said the tests will be introduced for passengers travelling from the main Ebola-affected regions in west Africa - Liberia, Sierra Leone and Guinea - where the death toll has reportedly risen to nearly 4,000, to give Britain an additional level of protection from the highly contagious virus.
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The screening will involve assessing passengers' recent travel history, with whom they have been in contact, and onward travel arrangements, as well as a possible medical assessment conducted by trained medical personnel.
Contingency planning is also under way, including a national exercise to make sure the country is fully prepared.
MP Keith Vaz, chairman of the Home Affairs Select Committee, welcomed the news but said the Government must learn lessons from its "delay in action".
He said: "I warmly welcome the Government's announcement which appears to be based on advice from the chief medical officer. This now places us on the same page as the USA and South Africa, which began screening in April this year.
"We need targeted, enhanced screening to reassure the public and to relieve pressure on the Border Force.
"As to whether more should have been done sooner on this matter, the time for an inquiry is not now, but we must learn lessons from this delay in action."