I had a useful email from Eurostar shortly after I called them.
Hopefully it will help someone else.
Thank you for booking your trip with Eurostar. Following the incident in the Channel Tunnel, we have been operating an amended timetable.
From 1 October we introduced a new timetable including additional services. We are operating 93% of the services we were running prior to the incident which means we are running up to 16 trains per day between London and Paris and 9 trains per day between London and Brussels.
As you booked a ticket before 1 October, your reservation has been transferred on to a service running under the new timetable. Please check the new departure time of your train by clicking on the link below.
If your service is no longer running or no longer calls at your station, you will have been transferred to the nearest departing service. Details of your new departure time and train number can be viewed in the link below. When you check in, you will be given a new boarding card with your new journey details and allocated seat reservation.
If your new train number is the same as your old train number (as on your confirmation email and your ticket) you have been reallocated the same coach and seat reservation and may check in as normal through the automatic gates. Please note your departure time may be different.
http://www.eurostar.com/pdf/reaccomodation/Reaccommodation_EN.pdf
Check-in closes 30 minutes before departure for Standard and Leisure Select customers and 10 minutes before departure for Business Premier and Eurostar carte blanche holders.
Thank you for your continued patience and understanding.
Eurostar
I found the pdf very useful.
Mel
