More than 100,000 Britons may need to be evacuated from the war-torn Middle East. Foreign Secretary Yvette Cooper indicated that 102,000 British nationals have registered their presence in the region. She said a total of about 300,000 British citizens are in Gulf countries targeted by Iran. British nationals are being advised to follow the instructions of local authorities and monitor the Foreign Office’s travel advice, which officials expect to change rapidly.

Those in Bahrain, Israel, Kuwait, Palestine, Qatar and the United Arab Emirates have been urged to register their presence with the Foreign Office online. The Government has used the registration scheme before to provide urgent updates to people affected by international crises, but it has not previously needed to deal with so many people in so many different countries.

Ms Cooper told BBC Breakfast: “The latest figure I have from this morning is we have 102,000 people (who) have responded to our proposal to ask people to register their presence so we know where they are, particularly in these Gulf countries that have been targeted so we know where they are and so that we can get them rapid information.

“In many of these countries the airspace is currently closed because of the Iranian attacks.

“This is deeply stressful obviously for people because we’re talking about a lot of people who are holidaymakers, who were transit passengers just passing through or people on business visits to the region and who we want to make sure can get safely home.”

Foreign Secretary Yvette Cooper has said no one would mourn the death of Supreme Leader Ayatollah Ali Khamenei but added the UK was not involved with what had happened.

Asked if the UK supports the way in which Iran’s de facto leader was killed, she told LBC: “No, that is not something that we were involved in.”

Asked if the Government supports the end result, Ms Copper said: “I don’t think anyone would mourn what has happened, because this is obviously part of a regime that has been not only brutally pursuing its own citizens, but also supporting terrorist activity across the region, destabilising activity through proxies across the region.

“But it is not something that we were involved in.”