From 14 November onwards, advance tickets on routes between London and Portsmouth and Southampton will cost between £1 and £10. More than 3,000 discounted tickets will be available each week on tickets bought on the internet.
The budget rail project is being piloted by Stagecoach, which runs South West Trains, and follows the launch of the company's low-cost bus service, called megabus.com, two years ago. The new service is called megatrain.com. More than 1.5 million passengers travelled on the discounted megabus.com services last year, which operates between 35 cities.
The company hopes to extend the cheap fares if they prove popular. Budget air carriers such as Ryanair and EasyJet have reshaped the airline industry - often making it cheaper to fly across the UK rather than take the train.
Stagecoach hopes to mirror the success of the airlines by attracting passengers who have been deterred by the high cost of rail travel. The company has said passengers will be seated in designated areas on some South West Trains. Passengers can already book their budget journey on megatrain.com for the second half of the month onwards. The discounted tickets will not be sold at stations and the offer will not be valid on Sundays.
A single fare from London to Southampton costs £25.30 during morning peak times.
"If you can offer prices starting from £1, it is within the budget of absolutely everyone," a South West Trains spokesman told the BBC. "We feel there is an untapped market with which we can fill the capacity of the rail market at these times."Reuse content