The repair bill following the fire could reach £50m
The firm that operates services through the Channel Tunnel has admitted it is losing almost £1m-a-day after a fire on board a train last September forced it to significantly cut its operation.
Eurotunnel says a full timetable for its services - and those provided by Eurostar from London St Pancras and Kent to Paris, Disneyland and Brussels - will be restored in February.
The BBC was given rare access to the tunnel severely damaged by the recent fire.
I am 40 metres below the seabed of the English Channel, 25 miles from Folkestone and about seven miles from Calais.
The tunnel resembles an impossibly long, giant Smartie tube.
Standing on a moving platform attached to a maintenance train, Eurotunnel's Chief Operating Officer, Jean-Pierre Trotignon, inspects the latest repairs.
"As you can see, this is more than just a hole in the ground," he says.
The fire on 11 September 2008 left 14 people with minor injuries.
Repair operations have been continuing 24 hours a day
The cause of the blaze, on a freight train travelling from England to France, is still unknown.
The cost however, is not, with the repair bill likely to be about £50m.
Up to 4,000 tonnes of concrete have had to be reapplied to the tunnel walls.
There were also 2500 wooden sleepers taken up as a result of the blaze, which forced the removal of 3,200 tonnes of chippings - laid down between the tracks - which were sucked up by a special vacuum train, to allow repairs to take place.
Since then, only around half the usual car and freight trains have been running and passenger services are less frequent and running more slowly.
The fact any services can run at all is because the Channel Tunnel is actually three tunnels. One for trains going north, one for trains going south, and a service tunnel - which is used by maintenance teams and can be used for evacuation in an emergency.
A section of the north tunnel, around two fifths of the way through from England to France, has been out of action since the fire, forcing trains going both ways to cross to the south tunnel for part of their journey.
But Mr Trotignon is pleased with how quickly his team of three hundred staff here have repaired the damage.
Working on a 24-hour, seven-day-a-week rota, they set themselves the deadline of completing the repairs in time for Valentine's Day and the February half term school holidays.
"This is a very important time of year for us in terms of traffic," Mr Trotignon told the BBC.
"The ski season is on, Paris is very popular for Valentine's Day, which is at the weekend this year, and the school holidays in the UK mean we will be very busy."
Miles of new cabling, which will carry 25,000 volts, have been laid
Behind us what look like two giant cotton reels of thick bronzed coloured wiring are slowly turning.
Workers in fluorescent yellow jackets and white hard hats dangle from cherry pickers installing the miles of new cabling that - at 25,000 volts - will power the trains.
"Once this is completed we will be doing some testing and then the last big job is to put the track back in," says Jean-Luc Pochet, Eurotunnel's Director of Maintenance and Infrastructure.
"That will happen in the next few days."
It will then be Jo Willacy's job, as the firm's Commercial Director, to persuade customers to return to the tunnel.
She, like her colleagues, is adamant the Channel Tunnel has been safe throughout the 10 years it has been in operation.
"We consider it one of the safest transport routes in the world," she says.
In business terms though, it has been tough.
"Clearly it is very dramatic when you lose 50 percent of your capacity overnight," she says.
"This has left a significant hole in our pockets. It's a difficult time."
All staff insist the firm does have adequate insurance - and can afford the repair bill.
But passengers will no doubt keep a close eye on ticket prices to work out if they are to be forced to foot some of the bill.
From 10 February car, freight and coach services through the tunnel will return to normal, with up to four trains an hour.
Passenger services on the Eurostar will also increase on the same day, before returning to full strength on 23 February.