In April 1937, the estimated cost of the proposed extension was £5,000,000 (approximately £349 million today) and the London Passenger Transport Board announced that, due to rising materials prices, the extension had been postponed until the Board's finances improved.
I april 1937 var den foreslåede forlængelses estimerede omkostninger £5.000.000 (omtrent £320 millioner i dag) og London Passenger Transport Board bekendtgjorde, at grundet stigende materialepriser var forlængelsen blevet udsat indtil organisationens finanser blev forbedret.