One hundred days before the start of the Paris Olympics 2024, Eurostar is predicting its busiest-ever summer peak.

The Games in the French capital run 26 July to 11 August, coinciding with the normal highest demand for the international rail firm, with many British families heading to continental Europe.

When the first tickets for trains between the two cities during the Olympics went on sale, they were booked at triple the normal rate.

Gwendoline Cazenave, chief executive of Eurostar, told The Independent: “When we opened sales in last November between London and Paris, we sold three times more tickets than we sell in the usual sales opening.

“We have already sold more than 400,000 tickets. So, yes, it’s gonna be a busy period. The trains are getting full really quickly. But we still have places.”

The cheapest return ticket from London St Pancras International to Paris Gare du Nord, travelling out the day before the opening ceremony and back on the final day of the Games, is £318 in standard class.

But that can be halved for shorter trips during the Olympics – such as £158 return between 29 July and 1 August.

Ms Cazenave said that passengers could well be travelling at the same time as competitors.

“We have 140 trains to Paris on which we’ll have athletes, so our customers will be able to meet athletes,” she said.

“The opening ceremony before the official opening ceremony in Paris will be on Eurostar.

“Returning home, these trains will be heavier because they will have medals on board: bronze, silver and gold.”

Flights between London and Paris are significantly cheaper than trains; flying out on 25 July, back on 11 August, the fare on Vueling from Gatwick to Orly airport, south of the French capital, is £204 return.

During the Games, Air France is offering a Heathrow-Paris CDG fare of £123 return from 29 July to 1 August.

These prices do not include the cost of travel to and from the capitals, nor anything more than modest cabin baggage.

Ms Cazenave said: “When you compare to airlines, you know that Eurostar is from city centre to city centre, with no added charges, no tax, no bag or seat [charges], no underground or taxis.

“It’s all included, and there’s no bad surprise.”

Tourism bosses in Paris are expecting a slump in the numbers of visitors staying overnight during the Olympics.

The Independent has been told that predicted hotel occupancy will be 60–70 per cent for the duration of the Games, compared with 91 per cent in July 2023.

All fares checked direct with operators on Wednesday 17 April