The state's Urban Development Minister Firhad Hakim told reporters in Kolkata that work for the project, being implemented by the Railway Vikash Nigam Limited (RVNL) was making a slow progress as adequate land was required for the project.
Sanctioned in 2010-11, the 32-km project is estimated to cost about Rs 4,260 crore.
The project still required 1,861 kottah land for its completion, which would cost about Rs 264 crore at the rate of nearly Rs 15 lakh per kottah, the minister said.
The Kolkata Municipal Corporation initially demanded a market price for the land. However, the RVNL was ready to pay only a token amount on the logic that metro was a public utility service.
The Housing and Infrastructure Development Corporation (HIDCO) had cleared the proposed Metro alignment on the important stretch from Salt Lake to airport via Rajarhat.