The Department for Transport (DfT) has confirmed security measures in the UK are now in place that require travellers to and from certain routes to be able to turn on any electronic items they wish to take onboard planes.
Transport secretary Patrick McLoughlin MP said that, in line with new requirements from the US Transport Security Administration (TSA), travellers in the UK must now adhere to these rules.
"Passengers on some routes may also be required to show that electronic devices in their hand luggage can be powered up or face not being allowed to bring the device onto the aircraft," he said.
"Passengers are therefore advised to make sure electronic devices being carried in their hand luggage are charged before they travel."
The confirmation comes after British Airways warned travellers they must be able to power up devices before boarding flights, in line with TSA regulations.
"Customers may be asked to turn on any electronic or battery-powered devices such as telephones, tablets, e-books and laptops in front of security teams and/or demonstrate the item's functionality," British Airways said.
"If, when asked to do so, you are unable to demonstrate that your device has power, the device will not be allowed to travel on your planned service." It added that broken devices are not allowed either.
Virgin Atlantic issued similar guidance. "To comply with new security requirements from the US government, customers travelling from the UK to the US may be subject to additional searches and questions," it said.
"Customers may be asked to turn on personal electronic or battery-powered devices in order to demonstrate how they work. If, when requested, you are unable to turn your device on, you will not be able to travel with your device."
The new rules come after the TSA said on Monday that US planned to stop visitors, travelling from "certain overseas airports" including London Heathrow, from bringing uncharged smart devices such as iPhones and Galaxy smartphones onto flights.
As well as requiring travellers to the US to have their smartphones charged, the new powers will also let airline security personnel put the devices through undisclosed additional screening.
"During the security examination, officers may also ask that owners power up some devices, including cell phones. Powerless devices will not be permitted onboard the aircraft. The traveller may also undergo additional screening," read the statement.
The TSA plans are part of a wider sweep of airport security reforms promised by secretary of Homeland Security Jeh Johnson on 2 July. The TSA said it will continue to develop new ways to bolster airport security and will announce fresh changes in the near future.
"TSA will continue to adjust security measures to ensure that travellers are guaranteed the highest levels of aviation security conducted as conveniently as possible," read the statement.
The news comes after widespread concerns about US intelligence agencies' use of smart devices in mass-surveillance campaigns, such as PRISM.
The campaigns saw the US National Intelligence Agency siphon vast amounts of customer data from numerous companies including Microsoft, Google, Yahoo and Apple. The campaigns are known to have targeted smart devices.
Alert Logic's vice president of research Will Semple told V3 the reforms are likely designed to find people using smart devices to circumvent airport security, as opposed to spy on incoming visitors to the US.
"The requirement to have all smart devices capable of demonstrating that it is functioning is the need behind the ‘charge' directive from the US Department of Transportation. It would also imply that the US intelligence agencies have a specific concern that smart devices are being utilised to bypass standard airport security detection systems," he said.
He added that the difficult nature of spying on incoming US visitors via their smartphones would be more trouble than it is worth for intelligence agencies.
"The concern around surveillance as a byproduct of this directive, where tracking can be carried out via public WiFi hotspots in airports is interesting. WiFi-only tracking as a means to track ingress and egress from an airport would produce a lot of data problems," he said.
"Assuming that the tracking agency has access to the logs from the public WiFi in near real time, they would need to have other data points to make decisions from. Even where public access WiFi requests users login with an email, these can be set up as ‘one-time uses' preventing basic correlation. The value of doing this type of surveillance can be limited by itself."
The news comes just after leaked documents emerged revealing that nine out of 10 people caught in the PRISM campaign were monitored by the NSA accidentally.