A new tube railway running from Victoria to Walthamstow was first proposed by a Working Party set up by the British Transport Commission in 1948. The main purpose of the line was to relieve congestion in the central area. The Private Bill needed to build it was introduced into Parliament in 1955. The Bill described a line from Victoria to Walthamstow (Wood Street). There was also a proposal for an extension from Victoria to Fulham Broadway station on the District line, but this was not included in the Bill.