Dr Howells said work was being done to ensure the fleet could run

Dr Kim Howells spent a day with South West Trains, which included a visit to Britain's newest train depot, at Northam in Southampton, home to the new generation of electric commuter trains.

South West Trains have purchased 785 new carriages in a �1bn deal, but very few of them can run without large-scale changes to the track.

Dr Howells promised that the work was being done to ensure the fleet of trains could run.

It's amazing really that the job wasn't done decades ago Dr Kim Howells

The government had planned to phase out old slam-door trains in the region by 2004.

This now looks highly unlikely as hundreds of miles of conductor rail and six electricity sub stations are needed before the full fleet can operate.

Dr Howells visited the brand-new training simulator in Basingstoke, where he experienced what it would be like to drive one of the new Desiro trains.

He then saw the trains themselves at the new depot in Northam.

He said: "It's amazing really that the job wasn't done decades ago - as trains have become more sophisticated, the demand for power has become greater.

"But it's being done now."

He confirmed that fares would probably rise before the work was completed to pay for the improvements.

"Huge numbers of people in this country don't use the railways - they drive, or walk instead.