Unions, politicians and many rail passengers are calling on the Government to delay the signing of a new franchise for the West Coast Main Line.
Virgin Trains is due to lose the service, which passes through South West Scotland and Cumbria, after First Group made a higher bid.
Labour wants the issue debated in Parliament. 140,000 people have signed a petition opposing the move.
First Group says its bid is deliverable and provides the best deal for taxpayers. It says it was selected in a fair, rigorous process that scrutinised best value and deliverability. It adds that it will be introducing major service improvements, new trains and will cut standard fares.