Eurostar trains are set to resume this morning after “unprecedented” flooding in a tunnel brought chaos for thousands.
The company said all services would run to Paris, Brussels, London and Amsterdam – but warned there could still be delays and packed stations.
Southeastern and Thameslink rail are also predicting serious disruption.
Travellers were stranded yesterday when all Eurostar trains to and from London St Pancras were cancelled.
Many were forced to frantically arrange a last-minute flight, ferry or road journey – with some people’s holiday plans ruined.
A man in St Pancras was seen holding an iPad reading “taxi to Paris”, while images showed the track near Ebbsfleet in Kent being deluged by a burst pipe.
Thames Water said it believed it was caused by a “fire control system and not a Thames Water pipe”.
Eurostar said on Saturday night that trains would soon resume after the problem was “brought under control”, adding that it was “sorry for the inconvenience”.
“At least one tunnel can now be used”, it announced, while still warning “some speed restrictions” in the morning could cause more delays and “very busy” stations.
Southeastern rail services were also disrupted by the flooding – and the company said problems were likely to linger on Sunday with a reduced service between St Pancras and Ashford.
“Whilst service recovers, trains running between these stations may still be cancelled, delayed or revised to terminate at Ebbsfleet International,” it said.
Thameslink is also predicting “major disruption” until the early hours of 1 January – due to a “shortage of train crew”.
Services between Bedford and London, Brighton and London, and Three Bridges and London are expected to be worst hit.
There will also be no overnight services on the network for people heading back from New Year celebrations.
A spokesperson for HS1, which runs the track between London and the Channel Tunnel, also confirmed the Eurostar line “will be operational in the morning”.
“We understand how frustrating this has been for passengers and apologise for the inconvenience caused at such an important time of the year,” the firm added.
The Met Office said bad weather was unlikely to have been the cause of the tunnel flood as there hadn’t been any heavy rain in the area at the time.
One of many travellers whose plans were ruined by the cancelled Eurostar trains was Matthew Hulls, 40, from Colchester.
He said he was “devastated” and had to return home after a surprise trip to Cologne for his partner was scuppered.
“My partner and I are big ice hockey fans of the local team and I’d purchased VIP tickets as a surprise for her, so (I’m) pretty devastated,” said Mr Hulls.
Read more from Sky News:
Get the latest weather forecast for your area
XL bully dogs must be muzzled and on a lead
It’s the second time this month that people have been left stranded due to Eurostar problems.
All services were temporarily suspended in the days before Christmas after an unexpected strike by French staff unhappy about their end-of-year bonus.
Meanwhile, with New Year’s Eve celebrations hours away, there could also be some disruption to road journeys as windy conditions and showers persist in many areas.
However, temperatures are forecast to remain warmer than normal and there are no UK Met Office warnings.