The order, which was confirmed yesterday (June 14), has been imposed since a suicide attack on a police bus carried out in November 2015.

The incident followed the terror attack in the resort of Sousse in which 30 British holidaymakers were killed, two years ago later this month.

After the extension was confirmed, the Foreign Office (FCO) said: “Since the terrorist attack in Sousse in June 2015 which targeted tourists, the UK government has been working closely with the Tunisian authorities to investigate the attack and the wider threat from terrorist groups in Tunisia.

“The Tunisian government has put in place additional security measures, but the intelligence and threat picture has developed considerably, including in neighbouring Libya.”

The FCO travel advice warned Britons travelling to the country that “terrorists are very likely to try to carry out attacks in Tunisia” and urged people to be “vigilant at all times”.

The only direct flights from the UK to Tunisia are currently operated by Tunis Air with a six-weekly service between London and capital Tunis.

The FCO advises against all travel to border regions between Tunisia and neighbouring Algeria and Libya and all but essential travel to the rest of the destination.

The FCO advice added: “Follow the advice of the Tunisian security authorities and your travel company, if you have one.

“If you choose to travel to or remain in Tunisia then you should check that your insurance policy provides adequate cover.”