When government posters recently appeared in Métro stations advising Parisians to work from home during the summer’s Olympic Games to avoid overcrowded public transport, Julie, 24, a support worker for refugees, was puzzled.

“It feels a bit like Covid lockdown all over again,” she said. “It’s like saying: ‘Parisians, stay confined to your homes, out of the way, while all this money is spent on the Games.’ Personally, I’ll stay away. I’m not happy about the idea of clearing homeless people from the city centre to make way for the Games.”

As Paris prepares for the Olympics and Paralympics, politicians, sports stars and the president, Emmanuel Macron, are trying to shore up public support for what is being billed as a “revolutionary” and radically different type of games – with half the usual carbon footprint and very little building, to avoid wasteful infrastructure investment.

Many Parisians are enthusiastic – of about 8m tickets sold so far, French people bought more than 3m, including 1.7m bought by people in the Paris region – but others in the French capital want to flee the city to avoid the mayhem, or rent their apartments at high prices. Anne Hidalgo, the mayor of Paris, recently urged its residents: “Don’t leave this summer. Don’t leave, it would be idiocy. This is going to be incredible.” Yannick Noah, the French tennis star and captain of the French men’s Paralympic tennis team, said: “The moaning has to stop … The whole world will be here … It’s going to be beautiful and I think there are lots of people who don’t realise that.”

Macron has called the Olympics the “pride of the nation”, as 300,000 people applied for 45,000 volunteer Olympics jobs. Paris bills itself as an Olympics “for the people” with amateur athletes from the general public for the first time able to run the Olympic marathon route by night. The two main construction projects, the Olympic village and the Olympic aquatics centre, both finished, are intended to boost low-income areas of Seine-Saint-Denis, north of the capital.

But with only a few months to go, challenges remain. The gigantic opening ceremony on the River Seine, in which 10,000 athletes on about 100 boats will float along 4 miles (6km) of water viewed by hundreds of thousands of spectators, remains a hard task. It is the first time an Olympics opening ceremony has been held outside the main athletics stadium. Airspace will be closed, with more than 45,000 police present. The interior minister, Gérald Darmanin, told the Senate this week that security for the Games was the “biggest logistic and security challenge” his ministry had faced. There will be 1m anti-terrorism checks and investigations in the run-up.

Whether the Seine will be clean enough to swim in for the triathlon and open-water swimming events is another key question. Swimming has been banned in the Seine over the past century because of dangerous pollution levels. But a frantic clean-up operation has seen work on water management and filtering stations in the hope of opening up the river for the Olympics and beyond. Macron has promised to swim in it himself. Key tests for bacteria will be undertaken in June and the main aim is to stop too much waste being washed into the river in the event of rain. The Brazilian Olympic champion open-water swimmer Ana Marcela Cunha told AFP this week that there must be a plan B – to hold the swimming events elsewhere – if the water was not clean enough. She said: “It’s not about erasing the history of the Seine. We know what the Alexandre III Bridge and the Eiffel Tower represent, but athletes’ health must come first.”

In a tense political climate before European elections, with Marine Le Pen’s far-right National Rally in the lead, rightwing TV pundits continue to bicker over the Olympics. There are rows over whether things are French and nationalistic enough, including speculation that Aya Nakamura, one of the most streamed francophone singers in the world, could sing Edith Piaf at the opening ceremony and the fact that the cross at the top of the Invalides building in Paris did not feature in the Olympics posters. Meanwhile, public transport, which in the initial Paris Olympic bid was going to be free, will instead double its ticket prices during the Olympics.

Hotel prices have rocketed. Research by Le Parisien found one hotel in the 15th arrondissement that cost €90 (£77) last summer will cost €1,363 during the Olympics. The initial surge in advertised hotel room prices, averaging about three times higher than the norm, has begun to drop slightly and stabilise.

The Paris Games are also under the most intense financial scrutiny of any Olympics, after organisers promised a transparent and ethical approach without the common problems of vast overspending and corruption. French financial prosecutors are investigating contracts over possible conflicts of interest and favouritism. The Paris 2024 organising committee, which is already subject to oversight by state auditors and the French anti-corruption agency, said it was cooperating fully. Another investigation is examining the way pay is structured for Tony Estanguet, the three-time Olympic canoe champion who is the Paris Olympics’ chief organiser. Estanguet, who is paid less than Sebastian Coe was when he served as chief organiser for London’s 2012 Olympics, has said he “doesn’t decide his remuneration or its structure”.

The government will next week hold urgent talks with trade unions over pay, conditions and overtime to try to avert potential strikes by public sector and transport workers during the Games. Police unions have already secured special bonuses for the period. When the government gave every primary school child in France a special commemorative Olympic €2 coin and booklet last month, some teachers’ unions complained that the €16m cost would have been better spent on schools.

Estanguet said: “It’s a little bit inevitable that such a big event raises questions and worries, and Paris is the same as previous host cities who also, at this stage, were asking how it would go … but, factually, the indicators are all very reassuring. The Olympic village was completed ahead of schedule. Six months before the Games, we’ve sold more than 8m tickets … 400,000 people wanted to run the marathon, more than 100,000 applied to carry the flame when we only have 10,000 places. We really feel a sense of enthusiasm …Everything is going according to plan, and that’s what’s important.”

The Olympics by numbers

• More than 16 million people are expected to visit the wider Paris region during the Olympics and Paralympics.

• 300,000 people are to attend the opening ceremony.

• 15,000 athletes will be competing.

• 5,084 medals will be awarded.

• 13m meals will be served to athletes at the Olympic village during the Olympic and Paralympic Games.

• More than 8,000 trees will be planted on the Olympic village site when the Games are over and it is transformed into a new residential, commercial and working neighbourhood in Seine-Saint-Denis.

• There will be 4 billion TV viewers worldwide.

(Sources: Explore France, Reuters, Paris 2024, Ile de France prefecture.)