According to the press office of the Mayor of Paris, Anne Hidalgo will dive into the waters of the Seine despite studies that do not always show 100% positive results in terms of pollution.

Despite a €1.4 billion investment to prevent sewage leaking into the river and improvements in pollution levels, the Seine has been a point of suspense in the run-up to the opening of the Paris Games. Heavy rainfall has caused bacteriological analysis parameters to exceed permissible levels, making swimming in the river unsafe for human health.

In other words, swimming is not advisable when it rains, even though the multi-million euro investment has improved the water quality. Mayor Hidalgo has promised to swim in the Seine to show that the river is fit for swimming.

Since the beginning of July, heavy rains have finally given way to drier weather, improving the water quality of the Seine. This has made it possible, for the time being and unless there are heavy rains, for the river to be ready for open water swimming and the triathlon, and for the 65-year-old mayor to swim in the Seine.

"On the eve of the Games, when the Seine will play a key role, this event is a demonstration of the efforts made by the city and the state to improve the quality of the water in the Seine and the ecological state of the river," Hidalgo's office said in a statement.

The city's Socialist leader had originally planned to swim last month, but had to postpone due to bacterial levels indicating the presence of faecal matter that were 10 times higher (and up to 13 times higher in some parts of the city) than permitted limits.

Hidalgo will be joined in the water by Tony Estanguet, former canoeist and organiser of Paris 2024, and the head of security for the Paris region, Marc Guillaume.

President Emmanuel Macron, who had promised to join the Seine swimmers, will be a notable absentee as the head of state is embroiled in a political crisis caused by his decision to call snap parliamentary elections last month.

Sports Minister Amelie Oudea-Castera became the first public figure to jump into the Seine on Saturday, with videos of her slipping on a footbridge and falling into the water while wearing a full wetsuit going viral on social media.

If weather conditions remain favourable, the Seine is expected to be used for the Olympic triathlon on 30 and 31 July and 5 August, and for open water swimming on 8 and 9 August.