After the formation of the London Passenger Transport Board in 1933, work to electrify the line from Liverpool Street to Shenfield began in association with the LNER. Progress had been halted by the war but work resumed after the end of hostilities. The line between Liverpool Street and Stratford was electrified from 3 December 1946, and the full electrification of the Shenfield line at 1500 V DC was completed by late 1949. At the same time, electrification of London Underground services in Essex and in northeast and east London led to the withdrawal of some services from Liverpool Street, being replaced with LU operations. Electrification continued with the line to Chingford electrified by November 1960.