Eurostar has recorded a 7% increase in sales in the first part of the year due to a surge in business travellers.
Sales revenue for the January-March period reached £227 million, a 7% increase on the year-earlier period.
Passenger numbers for the first three months of this year were up 3% to 2.3 million, with the number of business premier class travellers rising 6%.
Eurostar chief executive Nicolas Petrovic said, "The improvement we have seen in the corporate travel market in recent months underpins the strong performance reported today."
Travelers at St Pancras station have posted pictures of the scene on Twitter, with some describing the situation with the hashtag #chaos.
Eurostar told ITV News that customers have a choice of re-booking and getting compensation, or of a full refund, as well as being reimbursed for reasonable resulting accommodation costs.
Hundreds of travelers are queuing and waiting at St Pancras after severe delays meant a backlog of Eurostar services.
A fatality in the Lille region and infrastructure problems in the Eurotunnel mean few customers will be able to travel today, a spokesperson for Eurostar told ITV News.
Video footage shows the scenes at St Pancras, where some queues appear to stretch much of the length of the station.
There are "severe delays" on the Eurostar after a fatality and infrastructure problems in the Eurotunnel caused a backlog of trains.
Eurostar's twitter feed advises customers who are not currently at the station not to make their way there this evening, saying "we will be unable to accommodate you tonight".
It also says customers trying to contact them by phone could have to wait up to 20 minutes.
A fatality in the Lille region was followed by a technical hitch in the Channel Tunnel, resulting in a backlog of passengers on the tunnel's shuttles.
Eurostar say customers have a choice of re-booking their journey for free along with some compensation, or of getting a full refund for their journey.
They say they will also reimburse resulting accommodation costs.
Pierre Delalande from Eurostar said four trains in and out of England were affected, but that three of those had now reached their destination of London, while one was forced to turn back to the capital.
Trains do not run during the night and a full service is expected to resume this morning.
Mr Delalande said:
Customers were offered taxis and hotels where necessary, he added.
Eurostar has confirmed that a lightning strike close to the UK entrance of the Eurotunnel has set a building on fire. As standard procedure, Eurostar services have been stopped until the fire is brought under control. Fire services are at the scene, but the flames are not yet under control.
4 trains have been affected by the fire. 1 London to Paris train has turned around and been sent back to London. 2 Paris to London trains and a Brussels to London train are still being held at either end of the tunnel, but are said to be moving "soon". No trains are being held in the tunnel.
A lightning strike near Folkestone in Kent has caused fires at 5 railway substations. A freight depot nearby is also alight, which is believed to be causing delays on the Eurostar.
5 railway substations are on fire this evening after a lightning strike near Folkestone in Kent. Firefighters are tackling the flames along the line from Dover priory to Sandling station. Hundreds of passengers have faced long delays due to signalling problems since just after rush hour.
The Government will today raise the amount it expects to be invested in infrastructure projects in the UK from £309 billion last year to more than £375 billion.
Almost 300 of the 646 projects and programmes are already under construction.
Chief secretary to the Treasury Danny Alexander is expected to announce:
- The building of the UK's first toll road in a decade is to be scrapped. The A14 between Cambridge and Huntingdon will not introduce a fee for use after the improvement scheme, due to start in 2016, is completed.
- The railway station at Gatwick Airport will receive £50 million for redevelopment.
- A Government guarantee could support finance for the development of a new nuclear power station at Wylfa on Anglesey.
- The tube's Northern Line £1 billion extension to Battersea in south west London will be guaranteed.
- Improvements to the A50 around Uttoxeter in Staffordshire will start no later than 2015/16.
- A £10 million competitive fund to open in early 2014 to test ways to deliver superfast broadband to remote areas of the UK.
The Government is expected to announce plans to sell its 40% stake in the cross-channel Eurostar as part of a target to raise £20 billion through the privatisation of financial and corporate assets by 2020.
Danny Alexander, the chief secretary to the treasury, will announce the Eurostar sale as part of a wider £375 billion investment programme to 2030 and beyond, called the new national infrastructure plan (NIP).
Last month Eurostar revealed it had seen an increase in revenues and passenger numbers compared with last summer.
Sales revenue for the period July-September 2013 reached £207 million - a 10% increase on the same period last year - and passenger numbers in summer 2013 rose 5% to 2.7 million.