A new concrete pathway to facilitate wheelchair access to the Acropolis in Athens has fuelled a row between authorities aiming to broaden access to Greece's most famous ancient monuments and critics who say it ruins the classical harmony of the site.

Opposition leader Alexis Tsipras last month demanded the conservative government "stop abusing our cultural heritage," saying the changes would amount to "changing the landscape" of a world heritage site. But Culture Minister Lina Mendoni defended the development, which was approved by the Central Archaeological Council (KAS), the body which oversees the Acropolis complex that includes the Parthenon, a 5th century BC temple to the goddess Athena.

"I have seen people in wheelchairs who came up for the first time and felt happy," Mendoni told reporters during a visit to the site late on Tuesday. "I think this is something that should also make us particularly happy because to give joy to people is perhaps just as significant as the protection of our cultural goods," she said.

The Acropolis, a rocky outcrop with an ancient citadel and temple complex, has dominated the city of Athens for more than 3,000 years but reached its high point with the Parthenon, one of the supreme expressions of classical Greek culture. Now a protected UNESCO World Heritage site, it attracts thousands of visitors a day in peak periods, most of whom climb the 160-meter hill on foot and wander among the monuments on uneven stone paths worn smooth over hundreds of years.

The new walkway, a grey concrete track, is laid over a synthetic membrane that protects the ancient stones underneath and permits easy removal, said architect Manolis Korres, who is heading the project and has been doing restoration work on the Acropolis since 1975. It was opened to the public in March, replacing an older walkway from the 1970s which had worn away over the years.

As well as improving wheelchair access, other changes include a new elevator and golf carts with plans for tactile mobile models to allow blind people a fuller experience of the monuments. "I still think the Acropolis is very beautiful," said Michael Kirk, from the United States. "I don't think it's hurt the Acropolis at all."