The inquest into the killing of 38 holidaymakers - all of whom were Tui customers and 30 of whom were British - is due to begin on January 16 next year.
It will attempt to determine how much the UK government and travel firms knew about the risk of an attack on tourists holidaying in the North African destination.
Speaking to TTG at a Tunisian National Tourist Office media event in London, Sami Tounsi, trade manager at the Tunisian National Tourist Office said if Tui was deemed liable for not issuing its customers with enough security warning prior to the 2015 terror attack, it could make operators reluctant to return to Tunisia and nearby countries.
He also warned it would reinforce terrorism concerns that he believed many destinations were struggling against.
“I think if the inquest finds against Tui then it will make it very difficult for other operators to think about returning to Tunisia if the travel ban is lifted.
“It will mark the whole country and the region as a ’terrorism area’ and that will go against the travel industry as a whole.
Tounsi emphasised how far the Tunisian security services had come since the Sousse attack in June 2015 and the shooting at the Bardo National Museum in March of that year.
He stressed that the country had adopted a “proactive, not reactive” mind-set when it came to security and was constantly on the look-out for potential terrorist activity.
“We know that after what happened we must work hard to rebuild trust with British tourists so our focus is on establishing a strong security system,” Tounsi said. “Before the awful events in 2015 we had never experienced the horrific phenomenon of terrorism and so we have had to adapt and learn how to deal with these despicable acts.”