As part of Phase III extension of Delhi Metro, Mandi House was converted to an interchange station in order to reduce pressure on Rajiv Chowk station.[2][3] A new 6.8 km metro line connecting Central Secretariat to Kashmere Gate was completed in phases. The section from Central Secretariat to Mandi House was opened on 26 June 2014, followed by the stretch from Mandi House to ITO on 8 June 2015. The final segment, from ITO to Kashmere Gate, was inaugurated on 28 May 2017.
The new line runs on standard gauge and is integrated with the Badarpur corridor, which runs on standard gauge too.