 Notwithstanding considerable opposition, the Llanelly Railway (New Lines) Act 1861 was passed on 1 August authorising these routes.The Act separated the company for financial purposes into two undertakings, the "Original Line", and the "New Lines" (the Swansea line and the Carmarthen line).This seems not to have been intended for any other purpose than clarity of accounting, but it was later to encourage an unforeseen separation.