North West London Railway

From the Wikipedia page

The proposal to build a railway under the Edgware Road was revived in 1899 when a group of engineers began to promote the North West London Railway (NWLR). The railway would have followed a similar route to the ill-fated ER&VR, but was to begin further north at Cricklewood and would only run as far as Marble Arch. Its promoters included Sir Benjamin Baker, Sir Douglas Fox and Sir Francis Fox, and they had £1.5 million capital and sought to borrow a further £500,000. Although the bill to grant construction powers passed successfully through Parliament in 1899, there were difficulties raising the necessary funds. The only proven tube railway at the time, the C&SLR, was not delivering a great return on investment, and investors were hesitant. The outbreak of the Second Boer War in 1899 destabilised the money markets and construction on the NWLR project never commenced.[3]

In 1902 the scheme was allowed an extension of time to begin construction, and an increase in tunnel size from 12' 6" to 13' 0". The next year a bill was presented proposing an extension to Victoria Station, under Hyde Park and Grosvenor Place. However the bill was withdrawn following its postponement due to the London Traffic Commission. It was to transpire that the Commissions' only recommended new 'tube' would be an extension of the North West London from Marble Arch to Victoria. In 1906 the NWLR reintroduced its Victoria extension along with a reduction in tunnel size to 11' 8¼", receiving Royal Assent in August. However the financial conditions imposed on the Bill made the extension unattractive.