The council said the "controversial" system had "wreaked havoc" throughout the travel industry and should be replaced if there was to be any hope of saving "hundreds of thousands" of travel and tourism jobs in the UK.
It also warned that the UK could lose out on crucial funding, investment and spending if the government did not provide sufficient support for the sector.
The WTTC has also called on the G7, leaders of which will meet in Cornwall this week (11-13 June), to play a "critical role" in driving change to "save the global travel and tourism sector".
The WTTC advocates allow fully vaccinated travellers, and those with proof of a negative test, to travel to countries with similar or higher vaccination levels to that of the UK – and to destinations with low infection rates.
"Consumers, airlines and the wider travel sector were promised a [traffic light] watchlist and three weeks’ notice of any changes from green to amber – not just four days,’ said Virginia Messina, WTTC senior vice-president and acting chief executive, referring to the UK government’s decision to relegate Portugal to its amber list.
Of the traffic light system itself, Messina added: "It has been incredibly disruptive and costly for both travel and tourism businesses and consumers. It simply hasn’t worked."
The WTTC has also called on G7 leaders to take the lead on a coordinated response to a global resumption of international travel.
In an open letter to the G7, it calls for travel to be placed at the heart of global decision-making. "With the sector hanging by a thread, Boris Johnson is in a unique position to lead the G7 response to restart international travel and save the millions of jobs and livelihoods that depend on a thriving sector," said Messina.
"The situation is critical, so we must put travel and tourism at the heart of all governmental decision making globally and agree a consistent framework to reopen international borders."
Other measures put forward by the WTTC include commits to implement a consistent framework to safely reopen travel through the use of testing and digital health travel passes, and to reopen international borders between countries with similarly high rates of vaccination and low rates of Covid infection
"We urge Boris Johnson’s government, which led the world by administering the very first Covid-19 vaccination dose, and the other Leaders of the G7 to take this courageous step and save a sector which will be crucial in saving their economies," Messina added.
