The AC electrification of the eastern part of the North London line uses the previously unelectrified northern pair of tracks, which were also partially singled at the same time. Between and Highbury & Islington, there is a line which links to the East Coast Main Line at . This used to carry passenger trains to and from various main line stations (such as Edgware, Alexandra Palace, , and others) over part of the North London line to Broad Street Station; however, with the electrification of the Great Northern Electrics suburban lines in 1976, trains were diverted into and London King's Cross stations, so since then this link has only been used for freight trains. It too was singled concurrent with the AC electrification of the eastern part of the North London line.