The Russian plane that crashed in Egypt - killing all 224 people on board - at the weekend "may well have been brought down by an explosive device", Downing Street has said.
The spokesperson added: “We would underline that this is a precautionary step and we are working closely with the airlines on this approach.”
As a result, all flights between the UK and Sharm el-Sheikh have been suspended.
This suspension will continue until UK military personnel assess security at the Egyptian airport.
Ben Farmer, Defence Correspondent for The Independent, explained: “British military personnel have arrived in Sharm El Sheikh to help stranded British tourists.
“Defence sources said the small team of security and logistics experts were travelling with staff from the FCO and Department for Transport.
“They are expected to asses airport security and arrangements for getting tourists home.”
He added that RAF planes will not, however, be airlifting stranded Brits; instead, they will be working to secure the airport in Sharm El Sheikh.
He said: “The Ministry of Defence denied reports that C-17 planes were being readied to airlift tourists home.
“A defence source said the RAF has longstanding contingency plans for airlifting Britons home from crises around the world.
“However in this case, the scale of the number of people stranded meant it was expected be faster to ensure the airport in Sharm El Sheikh was secure and have the tourists fly back on commercial planes.”
EasyJet, Thomson Airways, Thomas Cook, Monarch, and British Airways are among those companies who have taken the Foreign Office's (FO) warnings against "all but essential" travel seriously.
As a result, they have cancelled all flights to and from the Red Sea resort.
There have also been reports that these flight disruptions could last until late December, as Foreign Secretary Philip Hammond told Sky News that the measures could last “days, weeks or months”.
He said he hoped things would be back to normal by the Christmas and New Year rush.
We will bring you more on this story as it develops.