Eurostar passengers are experiencing significant disruptions to their travel plans due to an issue on the French rail network. The problem is causing delays and cancellations on key routes, including services between London and Paris. Some trains operating between Amsterdam and Brussels are also affected. Eurostar has acknowledged the issue and is advising passengers to check their journey status before traveling. The cause of the French rail issue is currently under investigation, and updates are expected to be released as more information becomes available. Passengers are advised to allow extra time for their journeys and to monitor Eurostar's official channels for the latest updates.