Eurostar said it planned to run a full service on Wednesday but warned of possible knock-on disruptions after a power-supply issue halted Channel Tunnel train trips connecting London to the European mainland.

Travellers making journeys in the busy run-up to New Year had been left scrambling to find alternatives after the operator postponed all services between London, Paris, Amsterdam and Brussels.

"Services have resumed today following a power issue in the Channel Tunnel yesterday and some further issues with rail infrastructure overnight," Eurostar said in a statement posted on its website.

"We plan to run all of our services today, however due to knock-on impacts there may still be some delays and possible last-minute cancellations."

The service had earlier warned passengers to postpone their journeys to a different date and warned them of severe delays as well as last-minute cancellations.

Eurostar's site earlier showed that even services on the continent not using the Channel tunnel – such as ones between Paris and Brussels – had been cancelled during the day.

As well as the power problem, there was also a failed LeShuttle train in the Channel Tunnel, the 50-kilometre undersea rail link between Folkestone, in southeast England, and Coquelles, in northern France. (AFP)