The Channel Tunnel has reopened after a power cut caused huge delays for thousands of Eurostar passengers.
Customers were left stranded at St Pancras in London after trains to Europe were cancelled at 2pm today.
Within hours long queues developed near the departure gates as rush-hour commuters and those booked on evening trains poured in.
Passengers arriving for the 6.01pm service were being allowed to check-in.
But those who had tickets for earlier trains were being advised by Eurostar staff to queue and wait to see if they could claim any unfilled seats.
There were chaotic scenes as the barriers were opened to allow passengers on earlier cancelled trains to queue, with some pushing and heated exchanges with station staff.
Gary Warburton, 57, and his wife Visha said they had been waiting since 1pm, when they checked in for the cancelled 2.22pm Eurostar service.
Mrs Warburton said: "It was dreadful, completely disorganised. "First of all they should let the people on the three cancelled trains on first."
Mr Warburton added: "People jumped the queue because they didn't know there was a queue.
The issue also affected Eurotunnel, which operates freight and car services at Folkestone, Kent.
A message on the Eurostar website at 6.20pm read: "Due to a technical fault in the Channel Tunnel we have unfortunately had to suspend check in for all trains travelling this evening and we have had to cancel all services planned to depart before 18:00 UK time and 19:00 Continental time."