All air passengers flying into or out of British airports, and not just those on US-bound flights, must ensure their electronic devices are charged.
Advice issued at the weekend concerned passengers flying to the US, but on Tuesday night the British the Department for Transport widened the instruction to affect anyone flying into or out of the UK.
A spokesman for the department said: “In line with the US advice, passengers on some routes into and out of the UK may now also be required to show that electronic devices in their hand luggage are powered up or face not being allowed to bring the device on to the aircraft.
“Passengers flying into or out of the UK are therefore advised to make sure electronic devices being carried in their hand luggage are charged before they travel.”
No specific routes have been highlighted, and the spokesman said they hope to “minimise disruption as far as possible”.
New restrictions requiring all electronic devices, including mobile phones and tablets, to be charged so they can be switched on for security staff were announced by US authorities on Sunday.
The heightened security comes amid reports two terror networks are working together on a bomb that could evade existing measures.