Passengers on several Eurostar trains are facing delays and cancellations after a power supply issue on a rail line in northern France led to its closure.
The Eurostar website shows at least nine services on Monday between London and Paris have been cancelled, while a further 15 services have been delayed.
The problem started at about 08:30 local time (06:30 GMT) on Monday and disruptions are expected to continue until the end of the day, with trains being diverted to run on slower lines.
Eurostar has advised passengers to postpone their journeys if possible.
Some services between Brussels and Paris and between Amsterdam and Paris have also been cancelled, delayed or faced other disruptions due to the rail closure, which happened on the high-speed line between Moussy and Longueil in the Hauts-de-France region.
French track network operator SNCF said on its website that the “severely disrupted” services were due to a power supply issue which required “major repairs”.
It predicted delays of between one and five hours on the Eurostar, as well as its other services TGV inOui and Ouigo.
Trains between London-Amsterdam, Brussels-Amsterdam, Brussels-London and Brussels-Cologne have not been impacted.
Eurostar said SNCF had told it that one track would be reopened at 18:30 CET (17:30 GMT) and that this would “allow trains to run again on the high-speed line but with limited service”.
“Traffic should be able to resume on both tracks tomorrow morning when services start running again,” it added.
Extra staff have been sent to affected stations to help passengers.
August is a peak period for cross-Channel travel due to school holidays, meaning services are often busier than normal.
Monday’s disruptions come nearly a month after a Eurostar train travelling between Brussels and London had to be evacuated in northern France due to a power failure.
And in June, there were two days of major disruptions after separate fatal incidents on France’s LGV Nord line, which was followed by cable theft.