In response to acqua alta high tides, plans were drawn up to construct a four-foot-high glass barrier around the basilica, which sits at one end of St Mark’s Square, in the historic heart of the lagoon city.

But the companies that were contracted to protect the cathedral now say they are quitting the project because they have not been paid by the Italian state.

The work was meant to have started in August, paid for with €3.8 million (£3.24 million) in public funds.

“We never saw a single cent of that,” said Devis Rizzo, the president of one of the two construction firms that were contracted to carry out the work.

“Since September we have been paying our workers and suppliers out of our own pockets. We can’t proceed like this,” he told La Repubblica newspaper.

Carlo Alberto Tesserin, the president of the basilica’s governing body, the Procuratoria, said: “This arrogance and indifference is intolerable. Every day the sea erodes a piece of the basilica. The urgency of immediate action should be evident to everybody. The fact that we’ve lost two years (since the 2019 floods) is a scandal.

“The agony being suffered by St Mark’s is a symbol of the death of Venice.”

The inability of the authorities to protect the cathedral from further damage verged on the criminal, he said.