The GD&CR was authorised by Act of Parliament, but the rival Caledonian Railway (CR) had already had authorisation for building its line on the Annandale route; the GD&CR's financial position led it to abandon its intention of building an independent line to Carlisle, and it altered its plan so as to join the CR at Gretna Junction, relying on negotiating running powers for its trains to reach Carlisle.