Pécresse, who is head of the Île-de-France Mobilites (IDFM), has reportedly issued a letter to France’s Transport Minister Clément Beaune in a bid to securing the funding for the transport improvements.

According to Le Parisien, Pécresse called on the French Government to "respect its commitments and guarantee IDFM resources to finance both the operation of new metro and RER [Réseau Express Régional] lines and transportation for the 2024 Olympic and Paralympic Games."

The IDFM is the authority that controls and coordinates the different transport companies operating in the Paris area public transport network.

With around 600,000 travellers expected to use the network per day during next year’s Olympics, the IDFM has warned that the additional cost of regional transport caused by the organisation of the Games will be €200 million.

"At this stage, it is clear that no follow-up has been given to our request," said Pécresse.

"You cannot on the one hand tell us that it is urgent to take over, arguing that the Olympic and Paralympic Games start in less than eighteen months, and on the other hand again and again and always stay the rules financial matters."

The IDFM faces estimated financing requirements that will rise from €800 million (£700 million/$860 million) per year in 2024 to €2.6 billion (£2.3 billion/$2.8 billion) in 2031.

The Olympics and Paralympics are only a part of this.

Other factors include the repayment of the debt IDFM incurred during the COVID-19 pandemic - up to €130 million (£115 million/$140 million) per year for 15 years - and the cost of inflation.

The main factor is the rise in operating costs generated by the opening of new lines such as the Grand Paris express, extension work to the RER and the installation of new tram lines, which will be around €1.8 billion (£1.6 billion/$1.9 billion) in 2031.

The challenge for public authorities now is to find solutions to this financing requirement.