Venice should be added to a list of world heritage sites in danger, the UN’s cultural agency has said.

The iconic Italian city is at risk of “irreversible” damage from overwhelming tourism, overdevelopment and rising sea levels due to climate change, according to a report from Unesco.

The agency aims to encourage the better preservation of the site for future.

A spokesperson for the Venice municipality said they will “carefully read” the proposal, Reuters reports.

They added it will then be discussed with the Italian government.

Venice is known as “La Serenissima”, which translates to “very serene” – but that nickname no longer fits.

The Unesco report blames the Italian authorities for a “lack of strategic vision” to solve the problems faced by one of Italy’s most picturesque cities.

It is a blow for authorities, who are accused of failing to protect the historic city and surrounding lagoon.

But one of Venice’s former mayors has accused the international heritage agency of being “one of the most expensive and useless bodies on the face of the earth”.

Massimo Cacciari said Unesco passes “judgement without knowledge” and “give opinions left and right, which we would do best to disregard”.

“They don’t give us any funding to make changes, all they do is criticise… As if Venice needed Unesco to be a world heritage site! We need more action and fewer words.”

The inclusion of Venice in the danger list had already been proposed by Unesco two years ago, but it was averted at the last minute due to some emergency measures adopted by the Italian government.

In particular, one of those measures was the decision to ban large ships – such as cruise ships – in the San Marco Canal, as well as the promise to launch an ambitious conservation plan for the city.

The ban on large ships is being enforced – even though Unesco says it should be extended to other models of boats which are very polluting.

But the plan to save Venice was never implemented, and has remained a mirage.

According to Italian newspaper la Repubblica, Unesco experts have written several letters to the Italian government asking for updates and a timetable. The answers they received were deemed insufficient.

The Unesco report, seen by la Repubblica, says authorities dealing with the emergency in the city lack a strategy to address the threat of climate change.

A warming planet is having a damaging impact by causing sea levels to rise, so Venice – which is surrounded by water – is very vulnerable to flooding.

On top of this, about 28 million tourists visit Venice every year. This leads to more and more urban expansion projects, which in turn damages the city, according to Unesco.

Among other things, Unesco believes that high-rise buildings can “have a significant negative visual impact” on the city and they should be built far from the city centre.

Venice is considered an undisputed gem by Italians.

On top of being given a nickname for its serenity, it is in turn known as “the city of love”, “la domitante” (the dominant), and the “queen of the Adriatic”.