A draft contract drawn up by the director of passenger rail franchising shows that private operators will be entitled to increase fares for children from their current level of half the standard cost to two-thirds.
The contract was leaked to the Labour Party, which said it paved the way for substantial increases on all franchised lines.
That could mean a London-to- Southampton Network Away Break child fare rising from pounds 10.25 to possibly pounds 13.66.
The London-Edinburgh saver fare for children could increase from pounds 36 to a possible pounds 48, and the London-Inverness journey from pounds 41.50 to pounds 55.33.
Clare Short, Labour spokeswoman on transport, said yesterday : "Yet again ministers are promising one thing publicly - that they will act to increase rail use - while behind closed doors they are doing an underhand deal to charge the public more.
"Increasing child fares is just another Tory burden on families produced by Tory failure. Fares are going to be increased to provide a short-term profits boost for franchisees - and the rest of us are going to pay, through more traffic congestion."
The document sets out the basis of an agreement between the franchise director and LTS Rail for the operation of the London-Tilbury-Southend line.
It comes after the Government was forced to make a series of concessions over ticketing arrangements after privatisation. Ministers backed down on suggestions that a much reduced number of stations would be able to sell through-tickets. They also gave way over the threatened removal of passengers' rights to travel by any reasonable route.
Under privatisation, travellers will still be able to use a family Railcard, which entitles a child to travel for pounds 2 if accompanied by an adult, who in turn gets a one-third discount. However the pounds 20 card is only cost- effective for those who travel several times a year, and of no use to children who use the rail network alone.
A Department of Transport spokesman said: "It is silly to take one fare in isolation. There will be a whole range of regulated fares, which will be held constant for three years and then dropped by 1 per cent over the next two. And these are maximum fares."Reuse content