While the government was doing its best to recover parts of the fortifications that were in private hands, the planning authority’s practice of only scheduling parts of heritage gardens made the construction of flats in these gardens possible, Flimkien għal Ambjent Aħjar said.

It said in a statement that building more empty flats in heritage gardens, such as Villino Chappelle, Villa Bonici and Villa Mekrech, harmed residents’ health and undermined Malta’s tourism policy aimed at boosting tourism through the valorisation of heritage properties.

"It is just as unthinkable as building flats in Palazzo Parisio - a model of what can be achieved with such properties," it said.

It praised what it described as the recent move in favour of the preservation of heritage buildings but said that MEPA wasfailing in its responsibility to ensure that owners carried out at least basic maintenance of scheduled properties.

Old villas, it said, were being bought for the development potential of their large gardens, so their collapse through neglect would favour the owners.