Prime Minister David Cameron last night ordered flights to be delayed as a precautionary measure as he held a high-security Cobra meeting into the crisis.
A specialist British team has also been sent to assess security arrangements in the Egyptian resort while extra consular staff have been deployed to the airport.
Mr Cameron will hold face-to-face talks today with Egyptian president Abdel Fatah al-Sisi, who was due to arrive in the UK yesterday evening for a scheduled visit to the UK. The leaders spoke by telephone about the crash last night.
The Foreign Office estimated that there are around 22,000 Britons in Sharm el-Sheikh at the moment.
Thomson, which operates direct flights to Sharm el-Sheikh from Glasgow, said last night that it had temporarily suspended flights to and from the resort. Travellers have been advised to contact their tour operator.
The next outbound flight from Scotland was due to depart from Glasgow Airport at 7am today, with a return flight scheduled to land at 8:15pm.
A spokesman for Edinburgh Airport confirmed the next Thomson flight from Sharm el-Sheikh was due on Saturday.
A Number 10 spokeswoman said: “While the investigation is still ongoing we cannot say categorically why the Russian jet crashed.
“But as more information has come to light we have become concerned that the plane may well have been brought down by an explosive device.
“In light of this, and as a precautionary measure, we have decided that flights due to leave Sharm for the UK this evening will be delayed.
“That will allow time for a team of UK aviation experts, currently travelling to Sharm, to make an assessment of the security arrangements in place at the airport and to identify whether any further action is required. We expect this assessment to be completed tonight.”
All 224 people on board were killed when the Metrojet flight bound for St Petersburg from Sharm el-Sheikh came down in the Sinai desert on Saturday.
The nature of the crash and the lack of an SOS call have fuelled speculation that it was caused by a bomb or missile.
The visit of Mr al-Sisi to the UK has drawn strong criticism from human rights campaigners, with Labour leader Jeremy Corbyn accusing Mr Cameron of showing “contempt” for democracy by “rolling out the red carpet”.
Downing Street has insisted that “no issues are off the table” during bilateral discussions with the former head of Egypt’s armed forces, who overthrew Islamist president Mohammed Morsi.
Over the weekend a group in Egypt allied to Islamic State claimed credit for the atrocity.
The nature of the crash and the lack of a mayday have fuelled speculation that it was caused by a bomb or missile and the latest development followed US military surveillance evidence on Tuesday that a “hot flash” was detected on the aircraft moments before it crashed.
Transport Secretary Patrick McLoughlin insisted that the decision to suspend flights was based on concerns that had been raised rather than certainty over the fate of the Russian jet.
He said: “Safety will always be the priority and that is why the Prime Minister last night called president Sisi to express concern and to ensure that the tightest possible security arrangements were put in place at Sharm el-Sheikh.”