At the headquarters of the Paris 2024 Games, televisions predict the future. On one screen, Olympic athletes are travelling along the Seine in a huge flotilla, cheered on by close to half a million people in a mocked-up version of what organisers promise will be the most spectacular opening ceremony in history. On another, breakdancers are spinning at dizzying speeds on the Place de la Concorde. A third video mashes action with whooping crowds, tricolour flags, and more of Paris’s greatest landmarks.

The message is stirring and direct: after all the problems that blighted the Rio and Tokyo Olympics, from spiralling costs to corruption and Covid, the Paris Games – which start a year on Wednesday – will be a glorious reboot. Even if the threat of strikes, civil disobedience and terrorism still linger uneasily over the French capital.

“We are ambitious with these Games and there’s a lot of expectations,” says Étienne Thobois, chief executive of the Paris 2024 organising committee. “Paris is a fantastic city and a fantastic place to host the Games. The last few editions, for various reasons starting with Covid, have actually triggered a new hope. So we want a huge party. And we want that party to be extraordinary.”

However it won’t, organisers insist, cost the earth. In a significant shift in emphasis, 95% of the venues in Paris will be existing or temporary, with only the athletes’ village and aquatics centre being built from scratch. That means the Games’ planned budget of €8bn (£6.9bn) is considerably less than that of London, Rio or Tokyo.

The reboot has other fresh twists, too. That much is evident from an official Paris 2024 video, which ends by adding to the Olympic motto – “Plus vite, plus haut, plus fort – ensemble” (Faster, higher, stronger – together) – with new ambitions. They include aspiration to be “More brotherly … more bold … more wild … more urban … more inspired … more righteous”.

Such positioning will make some cringe. The Olympics? More righteous? Really? But Paris 2024’s official slogan, “Ouvrons grand les jeux” (Games Wide Open), also reflects the desire to deliver an event that is more inclusive, responsible and spectacular – and finds new ways to get people engaged before, during and after the Olympics.

“People don’t just want to be spectators,” Thobois says. “They also want to take part. I think that’s an evolution globally. So we decided that engagement was a key element both with the Games, but also with its legacy. We’ve been ambitious in the way we want to celebrate the Games but also in the way that we want to make a better world through sport, through the Games.”

Thobois insists those warm words are being backed up with action. Around 300,000 people will get free tickets to watch the opening ceremony as it moves three‑and‑a‑half miles along the Seine, accompanied by a dazzling artistic and music show. There is also Le Club Paris 2024, which offers points and potentially Olympic tickets to those who exercise regularly. A lucky group of 20,024 people will even get the chance to run the Olympic marathon on the same course – and on the same day – as the world’s best over 26.2 miles.

The route, which starts at Hôtel de Ville and goes to the Palace of Versailles and back, retraces part of the women’s march, one of the earliest and most significant events of the French Revolution in 1789. And notably, it will be the women’s race – not the men’s, as is traditional – that will bring these Games to a close.

It is an event that promises to be spectacular and historic but also brutal. As Jon Ridgeon, the World Athletics chief executive, also points out that the succession of hills on the course makes it “the toughest marathon in Olympic history”.

That race will certainly ask questions of the athletes. Before then, though, questions are being asked of the organisers after French police raided the Paris 2024 headquarters last month. It was part of two preliminary corruption investigations, looking into allegations of favouritism and misuse of public money in the attribution of construction contracts dating back to 2017 and 2022. Thobois’s home was also searched but he has denied any wrongdoing.

“We are probably the most watched and controlled organisation in France right now with the various entities,” he says. “There are internal committees, an audit committee, a remuneration committee and an ethics committee. All the safeguards and watchdogs are in place to make sure these Games run smoothly and are ethical.”

However the police investigation is not the only worry for organisers. In May, France’s National Olympic Committee president, Brigitte Henriques, resigned amid reports of intense infighting. Meanwhile the recent unrest across France has also led to concerns of trouble or strikes during the Games. But Thobois is optimistic on that front.

“We have a very vibrant democracy,” he says. “But the Olympics is special. We also have a very close relationship with the unions, they sit on our board and the discussion is constructive.

“Obviously they are careful, like the environmental organisations. They are really looking at what we’re doing and reminding us of our responsibility regularly and rightly so. But the dialogue is there and it’s constructive.”

The threat of terrorism means that an average of around 30,000 police officers a day will be mobilised during the Olympics, and Thobois insists that organisers are doing everything they can to ensure a safe Games.

Despite the hiccups, a recent poll found that support for the Olympics was nearly 70% among the French public, while organisers believe the 300,000 applications they received for 45,000 volunteer places is another measure of the Games having wider support.

Thobois is also keen to stress the legacy of Paris 2024, which will include 6,000 new houses in Saint Denis, one of the poorer parts of the city, when the athletes’ village is transformed into a new neighbourhood in 2025.

There will, he promises, be an environmental legacy too with the once heavily polluted Seine being safe to swim in for athletes. “Unless there is a huge flow of water falling for two days we are very confident. I will swim in the river, definitely. You know what? The day after the closing ceremony of the Paralympics, we’ll have a huge party in the water.”

Organisers also claim there will be “intangible” legacies too from the Games, whether from working with schools to have 60 minutes of physical activity a day to tackle obesity, creating running and cycling courses within cities, or introducing disability measures into their procurement strategy.

Time will tell. However, Sebastian Coe, president of World Athletics, believes Paris is on course to be a huge success. “After the necessary austerity of the Tokyo Games, there is high anticipation of a return to a full global celebration of the Games and the athletes in Paris,” says the man who knows a thing or two about such matters, having been in charge of London 2012.

Coe also believes that a lightning quick track at the Stade de France, along with the global stars and spectacular performances, will ensure track and field retains its pre‑eminence as the primary Olympic sport. “We look forward to welcoming hundreds of thousands of spectators to our road events on the streets of Paris and to Stade de France. We’re looking forward to writing a spectacular new chapter of our history within this magnificent stadium.”

For now, Thobois insists nothing is keeping him awake at night. “I don’t sleep a lot, but I sleep very well,” he tells the Guardian. “There are problems every day, but there is an ability to solve them day after day too and that brings us confidence.”

He pauses and smiles. “A project of that magnitude is complicated and challenging. But we are conscious that this thing is a bit special. It’s a once-in-a-lifetime experience as an individual, and once in a century as a country. And so we’re very excited. Very excited indeed.”