[2] In the mid-1930s, the Metropolitan line was suffering congestion at the south end of its main route, where trains from its many branches shared the limited capacity between Finchley Road and Baker Street.

To ease this congestion, new deep-level tunnels were constructed between Finchley Road and the Bakerloo line tunnels at Baker Street; then, commencing on 20 November 1939,[1] the Metropolitan's services toward Stanmore were transferred to the Bakerloo line (they are now on the Jubilee line) and ran to Baker Street through the new tunnels.

Upon the transfer, Marlborough Road station was closed and replaced by St John's Wood station, then on the Bakerloo line;[3] it had been little used, except (owing to its close proximity to Lord's Cricket Ground) during the cricket season.

The building housed a Chinese restaurant until 2009[4] and now contains a substation installed as part of the power upgrade programme to support the introduction of S stock on the Metropolitan line.

[3] Other Metropolitan line stations that closed with the opening of the new Bakerloo tunnels: