By Simon Montague BBC transport correspondent

Who will win control of the rail lines?

First Group, which runs trains on Great Western routes, is mounting a takeover bid for the East Coast Main Line, the BBC has learned.

First Group has been stung into revealing its hand after rival GNER, which currently runs east coast services, this week launched a grab for the Greater Western franchise.

First Group already carries passengers on parts of the east coast line, through subsidiary Hull Trains.

And it's due to take charge of the new Transpennine Express franchise early next year.

Customer service

But while First Group battles to extend its grip over the whole of the east coast route between Scotland and King's Cross in London, it's also raising the barricades.

GNER has joined forces with Chiltern Trains in an attack on Great Western's territory, covering lines between London, South Wales and south west England. The two companies are both highly regarded for customer service.

The Strategic Rail Authority, which oversees the train companies, has put the east coast franchise up for renewal in April 2005.