The state of emergency in Tunisia has been extended for a further seven months.
Thomas Cook became the first major UK tour operator to restart travel to the north African destination after a terrorist killed 38 holidaymakers, including 30 Britons, in Sousse in 2015. Flights resumed last month.
Tui, whose customers were killed in the attack, is set to restart with a small programme in May and holidays are on sale now.
The decisions by the operators followed a change in stance from the UK government in July 2017. It changed its travel advice for Tunisia meaning that it no longer warns British holidaymakers against travel to the majority of the country.
The state of emergency was first introduces after the incident at the Riu Imperial Marhaba hotel in Port El Kantaoui near Sousse in June 2015.
Latest Foreign and Commonwealth Office travel advice states that the Tunisian government has improved protective security in major cities and tourist resorts.
“But terrorists are still very likely to try to carry out attacks in Tunisia,” the FCO adds, saying that British tourists “should be vigilant at all times”.