In 1886, a further bill was submitted to Parliament to extend the tunnels south from Elephant and Castle to Kennington and Stockwell. This received assent on 12 July 1887 as the "City of London and Southwark Subway (Kennington Extensions, &c.) Act, 1887", allowing the construction of the extension to be added to the work on the original route, which had begun in 1886. The tunnels on this section were of a slightly larger diameter – and extended the line by a further . Before the railway opened, a further bill received assent, granting permission to continue the line south to Clapham Common. The act was published on 25 July 1890 as the "City and South London Railway Act, 1890", also effecting a change of the company's name.