The Union Ministry of Urban Development in a statement said it had earlier released Rs 300 crore, taking the total amount of its promised assistance to Rs 550 crore for the completion of the flagship project, which is a joint venture between the central and the Uttar Pradesh governments.
The statement said Home Minister Rajnath Singh, a potential Bharatiya Janata Party (BJP) chief ministerial candidate for the assembly polls, "has ordered speedy execution" of the 23-km long metro line.
The first phase -- between Transport Nagar to Charbagh -- is expected to open for the public in March 2017. Its first trial run was conducted on December 1 this year.
The union ministry said the Lucknow Metro is estimated to cost Rs 6,928 crore. Of this, the central government would provide Rs 1,003 crore as its share of equity, Rs 297 crore as subordinate debt and Rs 3,500 crore as loan assistance.
The Uttar Pradesh government has to mobilise the remaining Rs 2,128 crore as its share of equity.