Stephen Byers' refusal to hand over crucial documents about how he forced Railtrack out of business could result in a damaging court battle, it has emerged.

Railtrack's shareholders, who asked for the material, are now considering whether to issue a writ in order to force Byers to alter his stance. They are also thinking about whether to bring a charge of "misfeasance" - a legal term for abuse of power in public office - against the transport secretary.