Previously, the stretch from Thakurpukur to Majerhat was surveyed as a branch line of the circular railway, and a metro line from Majerhat to Dakshineswar via Sealdah (interchange with Line 2) was planned. This plan was scrapped and a new metro line from further south in Joka to BBD Bagh was sanctioned in 2010–2011 with a total length of at an anticipated cost of . Later the route was truncated to Esplanade. The corridor runs along Diamond Harbour Road, Khidirpur Road and Jawaharlal Nehru Road, major arterial roads of Kolkata, and has passenger interchange facilities with Line 1 at Esplanade. The proposed Esplanade station will not be the same as that of Line 1 but a different station which will also serve Line 2. The line will have a new depot in Joka. Due to land acquisition problems, construction has been delayed several times since 2017. The work resumed in several phases and new bids were invited by Rail Vikas Nigam Limited (RVNL) in April 2020. It is India's first metro line to run on indigenous head hardened rails, manufactured by Jindal Steel & Power.