A ceremony at an undisclosed location near Ashford in Kent this Thursday will mark the official start of construction.
It will end two years and eight months of wrangling, political negotiations and backroom deals to ensure that the 68-mile stretch of track is built.
But it has reawakened fears among residents and businesses that they face more years of uncertainty because of the rescue plan agreed by the Government, and a fresh legal battle is looming.
Shareholders are tomorrow expected to give the go-ahead for a complex financial deal enabling Railtrack to take over the project.
Railtrack will buy the 43-mile section of the route, from the mouth of the tunnel near Folkestone to Ebbsfleet in north Kent, for pounds 1.5bn in 2003. The company has also taken an option to buy the final, more complex, stretch to London St Pancras for pounds 1.8bn in 2006.
People living near the first section are trying to minimise the environmental impact from the high-speed trains. Those near the proposed route of the second phase, mainly in west Essex and east London, do not know whether Railtrack is interested in the line past Ebbsfleet.
Geoff Fleming, chairman of the CTRL Action Group, which represents 32 businesses, said: "On the Essex side people who have lived through years of blight now face another six.
"These businesses can't develop, they can't have normal relationships with their banks because their land is worthless and they have poor relations with their staff. They are slowly being bled to death."
Hundreds of residential houses and 60 businesses are affected, especially from the Dartford bridge to Barking, where the tunnel under east London will dive underground. One estimate has put possible job losses at 5,000.
Mr Fleming's group wants a judicial review of the Act that gave Union Railways, a subsidiary of London & Continental Railways, (LCR), power to purchase land.
Andrew Brice, of North Downs Rail Concern, which acts as an umbrella for action groups in the area between Ashford and the Medway, said residents feared the noise of the 186mph trains.
"It is not just a train, it is immensely noisy," he said. "It is like standing on the runway at Heathrow. He is apprehensive that Railtrack, which takes the financial risk of project over-run, would be tempted to "build it on the cheap".
Local groups and councils have already won concessions and environmental safeguards from the company. Construct-ion of the first section is scheduled to take three years, with the track-laying beginning in 2001. After tests, it should open in 2003.
Tunnelling on the second section into London is scheduled to start in 2002, with track work beginning in 2004, the St Pancras terminal opening in 2006 and the section in 2007.
When the line from St Pancras is completed, it will cut the journey to Paris to two hours and 20 minutes, a saving of 35 minutes.Reuse content