Ministers are facing calls to give train operators more say over signalling and track on Britain's rail network.

In a paper presented to the Department for Transport, the Association of Train Operating Companies argues that operators should have more freedom to decide levels and quality of services on their particular route.

It comes as transport secretary Alistair Darling begins a series of seminars to determine the future structure of the rail industry.

In addition, London mayor Ken Livingstone is due to outline his plans to take over responsibility for franchising London rail services.