PARIS, France (AFP) — The chief organizer of the 2024 Paris Olympics insisted that there were no plans to move the opening ceremony of the Games from the river Seine amid ongoing speculation about the hugely ambitious water-based show.

After months of denials that contingency plans were being put in place, French President Emmanuel Macron sparked new doubts last month when he said that there was "obviously a Plan B, a Plan C" for the opening ceremony on 26 July.

But Tony Estanguet, who heads the Paris Olympics organizing committee, stressed that the location for the ceremony would not change.

"Today, with the artistic director for the ceremony, Thomas Jolly, we are working on an opening ceremony on the Seine. Our teams are not working on any other location," he told France Inter radio.

French security services have consistently raised doubts about having the opening team parade on the river in the heart of the City of Light, citing the difficulty of securing such a large area and the risk of a terror attack or stampede.

With sporting delegations set to sail along the river in a flotilla of around 100 boats, it will be the first time the opening ceremony has taken place outside the athletics stadium in Olympic history.

French Sports Minister Amelie Oudea-Castera called the plans "a key symbol of our ambitions for iconic Games" in an interview earlier this month.

Some media reports have speculated that the ceremony might simply be downgraded in the event of a major terror threat, with the number of spectators limited or just performers, not athletes, permitted to take part.

As many as 45,000 members of the French security forces will be deployed during the Games alongside tens of thousands of private security guards.

Tense negotiations between the government and police trade unions over Olympics bonuses are underway, with one union holding a first protest on Wednesday to demand a one-off payment of 1,500 euros per officer.

Health workers, railway staff and other public sector staff from street cleaners to metro drivers are all formulating bonus pay demands, with Macron's centrist government desperate to avoid strikes or disruption during the global showpiece.