The final section of the Folkestone to London Channel Tunnel Rail Link is to open in a year's time - 14 years after the high-speed line opened in France.
Ebbsfleet International Station will open on 14 November 2007
Train operator Eurostar said its 186mph trains would start using the final section, from Ebbsfleet, in north Kent, to St Pancras, on 14 November 2007.
The opening of the final stage will cut journey times from London to Paris from 2hr 35min to 2hr 15min.
The first phase, from Folkestone to Ebbsfleet, opened in September 2003.
"This move will be the most significant event in Eurostar's history since we started running passenger services 12 years ago today," said chief executive Richard Brown.
"It will mark the start of a new era in travel between the UK and mainland Europe, making high-speed rail an even faster, more reliable and less environmentally damaging alternative to flying."
Eurostar trains will continue running into Waterloo until 13 November 2007.
Waterloo's international terminal will then be handed back to the government, which has promised to use the platforms to reduce congestion for domestic commuter trains.
Eurostar is also to run services from £100m Ebbsfleet station to Paris and Brussels, but is to cut the services it currently runs from Ashford in Kent.
The opening of the Ebbsfleet to St Pancras section will also cut the journey time from London to Brussels, from 2hr 15min to 1hr 51 min.
Eurostar trains will run to St Pancras when the link is completed
High-speed domestic services will start using the new section from 2009.
The Channel Tunnel Rail Link is also now being rebranded as High Speed 1, or HS1.
Its completion will finally put the UK on a par with France and Belgium.
The French had their high-speed rail link ready in 1993 - a year before the Channel Tunnel opened, while the Belgian high-speed link was completed in 1997.
Mr Brown said St Pancras International station would be "stunning", with connections that would make Eurostar accessible to millions of new customers across the UK.
"We will be competing head-on with regional airports, with comparable city centre-to-city centre journey times," he said.