The travel industry risks going back to the "medieval age" if its demands are not met when Britain leaves the European Union, tour operator Thomas Cook's chief executive has stated.
Peter Fankhauser said Europe must have a single aviation market and transitional agreements for air traffic rights after Brexit.
He added that it was imperative for the sector to co-ordinate and make its voice heard as negotiations begin.
"Can you imagine needing again a visa to go to Germany? That would re-draw the map back to the medieval age," the Swiss CEO told Association of British Travel Agents (ABTA) delegates.
"We have absolutely no excuse not to join forces to make our voice heard. We have to explain what we need and what the impact will be - on both sides of the Channel - if we don't get what we need," he said at the conference in London.
Travel firms and airlines have been vocal on the risks that Brexit poses the industry, with Ryanair chief Michael O'Leary warning that a worst case scenario could see a total end of flights between Britain and the European Union.
Britain is due to exit the European Union in March 2019.
With bookings for summer 2019 due to open near the end of this year, the industry is looking for a swift deal for the sector now that negotiations between the EU and Britain are under way.
