In 1792 the promoters sought an Act of Parliament urgently, as proposals by the Leeds and Liverpool Canal to alter their route would have affected the profitability of the southern section. It received the Royal Assent on 11 June 1792, and was entitled "An Act for making and maintaining a navigable canal, from Kirkby Kendal in the county of Westmorland, to West Houghton in the county palatine of Lancaster, and also a navigable branch from the said intended canal at or near Barwick, to or near Warton Cragg, and also another navigable branch, from, at or near, Galemoss, by Chorley, to or near Duxbury in the said county palatine of Lancaster."