In comments likely to alarm diplomats, Iranian President Masoud Pezeshkian told Prime Minister Sir Keir Starmer it has a "right" to attack Israel over the assassination of a Hamas leader in Tehran.
UK officials are now considering whether they will need to bring thousands back in the event of hostilities.
Embassy teams have been bolstered to assist with emergency plans and Border Force teams have also been sent to the region as they were during the evacuation of Sudan and Afghanistan.
More than 1,000 military personnel have already been put on standby to possibly get Britons out of Israel and Lebanon, defence sources suggested.
A Government spokesman said: "While we continue to use all diplomatic levers to push for de-escalation, our staff are working around the clock to plan for all scenarios to keep British nationals safe. Our travel advice is constantly updated to reflect the latest guidance." Western leaders have been urging the Iranian regime not to trigger an all-out regional war.
Intelligence experts have become increasingly concerned that Iran is ramping up preparations for a possible attack following the death of Hamas's political leader Ismail Haniyeh in Tehran.
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Denne historien er fra August 14, 2024-utgaven av Daily Express.
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