A general view shows St Mark's square on September 3, 2023 in Venice.
A general view shows St Mark's square on September 3, 2023 in Venice. AFP

Venice will trial a long-debated ticketing system from spring next year, officials said Tuesday, with day-trippers charged five euros to enter the Italian city's historic centre in attempt to cut tourist numbers.

The council executive backed the move just weeks after UN cultural agency UNESCO recommended Venice be added to its list of world heritage in danger, in part because of the impact of mass tourism.

"Regulating tourist flows in certain periods is necessary, but that does not mean closing the city," said mayor Luigi Brugnaro.

"Venice will always be open to everyone."

The plan, which has long been mooted, must still be approved by the wider city council, which meets on September 12.

And many details are still unclear, notably on how many tickets will be available.

But the council executive on Tuesday agreed to a 30-day trial, likely spread out across public holidays and weekends in the spring and summer of 2024.

Residents, commuters, students and children under the age of 14 will be exempt, as will tourists who stay in the city overnight, the local authority said in a statement.

"The objective is to discourage daily tourism in certain periods, in line with the fragility and uniqueness of the city," it said.

With the new system, Venice will become a "trailblazer on the global level", added Simone Venturini, the city's council member for tourism.

He said it was not about making money -- with the proposed five-euro fee only covering costs -- but finding a "new balance between the rights of those who live, study or work in Venice, and those who visit the city".

Venice authorities have for years sought to ease the pressure of the vast numbers of tourists who flock to see sights including the Rialto Bridge and St Mark's Square.

The ticketing plan has been repeatedly postponed over concerns it will seriously dent tourist revenue and compromise freedom of movement.

Two years ago, the city imposed a ban on massive cruise ships, from which thousands of day-trippers emerge daily, rerouting them to a more distant industrial port.

The aim was also to reduce damage from the large waves caused by the ships, which are eroding Venice's foundations and harming the lagoon's fragile ecosystem.

But the tourists still come, with around 3.2 million staying overnight in Venice's historic centre last year, according to official data.

UNESCO put Venice on its heritage list in 1987 as an "extraordinary architectural masterpiece", but it has warned of the need for "more sustainable tourism management".

On July 31, it warned the city risked "irreversible" damage due to a string of issues ranging from climate change to mass tourism.

The recommendation that the city be added to its list of world heritage in danger will be discussed at a meeting of UNESCO's World Heritage Committee in Riyadh later this month.