Ahead of tomorrow's publication of the government's draft 30-year plan for Britain's railways, the Rail, Maritime & Transport (RMT) union said the 'fragmented, expensive and failed franchising system' must be ended to increase rail use on the scale required by the economy and the environment.

The government is expected to use the announcement to give the go-ahead for the long-delayed Thameslink 2000 scheme to improve capacity on a rail artery through central London.

However, there are fears that ministers will cave in to pressure from train operators to deregulate Saver fares, which could result in massive rises in many 'walk-on' rail fares, which can be bought and used on the same day.

The government has already given its blessing for inflation-busting fare rises as part of a string of recently approved franchise deals.

The RMT welcomed the expected increases in capacity on the network, but warned that expecting passengers to absorb ever-increasing fares would force people onto the roads.

RMT general secretary Bob Crow said: 'Our rail fares are already among the most expensive in Europe and the ludicrous franchise deals signed off in recent months will mean massive hikes year on year. That is the reverse of what should be happening and it has to stop.'