In the heart of ancient Athens, on narrow streets and around archaeological sites, visitor groups appear to be everywhere, snaking their way behind tour guides.

Previously, officials would have welcomed such scenes. But for Haris Doukas, the socialist mayor who is determined to reclaim the capital’s congested city centre for its citizens, the start of tourist season leaves the city at risk of “over-saturation.” Entire neighbourhoods, he believes, are in danger of losing their authenticity because of uncontrolled tourist development.

“Athens cannot operate as if it were a giant hotel,” he said in an interview. “Restrictions and rules are needed. Cities must also have a say in the way they develop.”

Last year, more than 8 million people visited Athens, a record for a city that not long ago was regarded as a pit stop to the Greek isles. In short-term rentals alone, overnight stays in the popular Plaka district beneath the Acropolis have more than doubled since 2018, a study commissioned by the municipality recently revealed.

In the city’s neo-classical town hall, officials say time is of the essence if Athens is not to fall victim to its own success. The warning signs are everywhere: from soaring property rents that have priced out local people, to overstretched infrastructure buckling under the pressure.

“All of Athens is being dug up so that we can cope,” said Doukas, who was a climate energy professor before he went into local government. “We’re building electricity infrastructure, water systems, new drainage, 5G networks. When you have around 700,000 residents and 8 million visitors, the pressure is enormous.” Every month “more staff, more equipment, more machines” were being taken on to meet the challenges.

Doukas assumed the post in 2024 after unexpectedly cruising to victory with the support of the main opposition Pasok party, on a pledge “to green” what is widely seen as the continent’s hottest capital. An estimated 3,855 trees have been planted around the 15 sq mile (39 sq km) municipality under his watch.

But as Athens’ appeal has grown, the mayor has found himself coming head-to-head with the forces he blames squarely for “runaway development” in prime tourist spots. Doukas has had his sights on construction companies that are determined to erect multi-storey buildings at the foot of the 5th century BC Acropolis, as well as property investors and entrepreneurs. He is also taking aim at the proliferation of often unlicensed roof-top bars and eateries.

The battle intensified this week as Doukas told the Guardian he would use a tourism land-use bill, currently under debate, to call for a blanket ban on new business activity in the city’s historical centre.

“We’ll be stopping all tourist investment in Plaka, which I am on a mission to save. There’s no more room. Not for short-term rental, not for serviced apartments, not for hotels, or any other tourism use. The area is over-saturated,” he said. “We want to say ‘enough is enough’ in a bill that is enshrined in law.” Investors, he said, should head to other “less congested” areas of the capital.

The mayor has also floated the idea of freezing construction permits for new hotels. That would follow a similar ban, introduced by the centre-right government, curbing short-term rentals in neighbourhoods within view of the Acropolis.

To his surprise, this week he won support from an unexpected quarter. At an event promoting the capital on Tuesday, the head of the powerful hoteliers’ association, Evgenios Vassilikos, also raised the prospect of a cap on hotel construction, citing the example of Barcelona, which has not issued licences for new hotels since 2017. “We don’t need to reinvent the wheel,” said the hotelier, adding that the moment had come for the capital’s tourism sector to seriously contemplate where it wanted to be in 10 or 15 years’ time.

The mayor said: “When the whole of Athens’ centre is turning into a hotel zone, I cannot be the only one saying it. Now that the president of the hoteliers’ association has weighed in, the discussion has officially begun. Athens cannot become [another] Barcelona.”

Doukas has clearly been emboldened by Jaume Collboni, his left-wing counterpart in Barcelona, who recently announced a complete ban on short-term rentals from November 2028, when permits for more than 10,000 apartments will be rescinded in an attempt to make the city more livable for its residents. Both Athens and Barcelona are among 15 cities whose mayors have joined a European housing action plan that has urged the EU to take bold initiatives to address the crisis.

Like Collboni, Doukas has described access to affordable housing – impossible for many because of short-term rental pressure – as the municipality’s biggest problem.

“We’ve created a social housing office to identify buildings and apartments that we can renovate with EU funds,” he said. “We want to incentivise young couples to remain in the centre. While other cities are moving toward cement and skyscrapers, we’re moving in an altogether other direction, and that includes demolishing buildings to create public space for parks and playgrounds. Athens is for its people. It is not only for those who simply want to exploit it.”