Eurostar passengers are braced for more possible delays and cancellations after the train network was forced to cancel large parts of its London-Europe service on Tuesday.

Train services to and from continental Europe - on both Eurostar and Le Shuttle - were suspended for much of the day after a power supply failure due to a technical fault and a failed Le Shuttle blocking all routes.

The disruption upended New Year's plans for thousands of passengers in London, Paris, Brussels and Amsterdam during ⁠one of the busiest travel weeks of the year.

Repairs are under way to try to fix the issue.

Eurostar said it was resuming some of its services gradually around 3pm on Tuesday, but passengers were urged to stay away.

As of the early hours of Friday, the first Eurostar trains to Paris, Brussels, and Amsterdam around 6am show as cancelled, while Le Shuttle records delays of at least an hour to people's booked departure times.

Image: Delayed passengers at St Pancras train station, central London, after Eurostar services were cancelled on Tuesday. Pic: PA

Eurostar told passengers: "As the overhead power supply issues in the Channel Tunnel still remain, only one line is available to run trains on.

"This means there will continue to be delays and longer journey times than usual this evening.

"Therefore, we continue to advise our customers to rebook their journey for another day if possible, with free exchanges available.

"We also advise customers not to come to our stations if their trains have already been cancelled."

It added: "Although outside of our control, we apologise for the disruption today and will continue to keep customers updated with the latest information and support them with rescheduling their bookings."

Image: Travellers queue for Eurostar services at St Pancras International station in London. Pic: AP

Getlink, which operates the tunnel infrastructure, said repairs to the power supply were under way and that traffic services were slowly being restored in both directions.

"Our teams are working to restore the situation as quickly as possible. Waiting times will be adjusted throughout the day," the company added.