Transport minister John Spellar attended a ceremony in Kent on Tuesday to mark the completion of part of the Channel Tunnel Rail Link.

The 46-mile stretch is the first substantial section of a mainline railway to be constructed in Britain for more than a century.

The ceremony, held in Mersham near Ashford, marked the end of the civil engineering on one section of the project

Running between the Channel Tunnel at Folkestone and Fawkham Junction in north Kent, the route will enable Eurostar trains to run at full speed in Britain for the first time.

Passenger benefits

The section will be operational in the autumn once signalling has been installed and full testing of trains has taken place.

When completed the Channel Tunnel Rail Link will be 68 miles long and run from St Pancras station in London to the coast.

It is being built in two parts by London & Continental Railways with section two due for completion at the end of 2006.

Chris Jago, managing director of Union Railways, which is in charge of stage one, said the benefits for passengers would be seen in the future.

Speaking on BBC Radio Kent, he said: "The major saving comes in 2007 when we open up the last section through to St Pancras which will not only give us a quarter of an hour saving on the international times but will also give us dramatic savings within the area of Kent."