changes to the plans for the Wimbledon to Sutton line. The C&SLR was an underground railway running in deep tunnels. In 1922, its line ran from Euston to Clapham Common. The C&SLR proposed to extend it for "6 miles, 1 furlong and 7.2 chains" () from Clapham Common through Balham, Tooting, Merton (South Wimbledon) and Morden, to connect to the route of the W&SR and then continue to Sutton. The LER, C&SLR, and DR would invest in the construction of the W&SR, for which the estimated cost had risen to £1.7 million (approximately £ today). The DR would operate trains over the W&SR from Sutton to Wimbledon and thence to Central London; the C&SLR would operate trains over the southern end of the W&SR from Sutton to Morden, then via the new C&SLR extension to Clapham Common and northwards. The plans also included the construction of a depot at Morden for use by DR and C&SLR trains. The Southern Railway (SR), successor to both the L&SWR and the LB&SCR under the 1923 grouping of railways, objected to the plan to extend the C&SLR line to Sutton – Sir Herbert Walker, General Manager of the SR, described the proposals as an "invasion" of the SR's territory allocated by the grouping agreement. Walker proposed a limited extension of the CS&LR as far as Tooting and offered to allow the C&SLR's trains to run to Wimbledon via a connection to the SR's Tooting to Wimbledon line. He also proposed that the SR should build the W&SR instead. The UERL rejected Walker's plan, claiming that the entire extension to Morden was needed as that was the only place to build the necessary depot. Without the compromise arrangement, the House of Lords rejected the whole scheme but the House of Commons, which wanted the Underground's service to be extended from Clapham, encouraged further negotiations between the UERL and SR. In July 1923, an agreement was made that the SR would withdraw its objection in exchange for a transfer of the UERL's interests in the W&SR. The District railway would be allowed to operate to Sutton via the W&SR route, although this was not pursued further. The Wimbledon and Sutton Railway Act, 1923, the London Electric Railway Act, 1923 and the City and South London Railway Act, 1923 all received Royal Assent on 2 August 1923. The SR arranged for the take-over and winding-up of the