Castleman realised that he needed the support of a larger company, and the LSWR was the obvious choice, as it would bring London traffic to them at Southampton, and enable them to extend to Exeter. He approached the LSWR with the idea but was rebuffed; evidently they wished to concentrate on reaching Exeter through Salisbury, and they hinted at branches from such a line into Dorset. In the ensuing controversy, Castleman's route became known as "the Coastal Route" to Exeter, and the route via Salisbury "the Central Route". Castleman realised that it was unlikely that both routes would be built, and he pressed the LSWR for undertakings not to develop the Central Route; the larger company again rebuffed him and declined further discussion.