Metro tracks will finally be built under the Maidan for the Joka-Esplanade project with the railway ministry approving additional funds for building the tracks, an official said on Wednesday.

In a letter to Calcutta Metro, the ministry has allocated Rs 2,825 crore for building 6km of tracks underground, said an official. Initially, the railways had allocated around Rs 650 crore for the viaduct till BBD Bag.

The project was stalled since 2011 because of a stand-off between the railways and defence ministry and construction could take place only between Joka and Majerhat.

Initially, the plan was to build a viaduct but the army, which is the custodian of the Maidan, had objected to the plan. The defence ministry had agreed to allow tracks of the Joka-Esplanade Metro to go through the Maidan in 2015, ending a four-year stalemate. This was after Prime Minister Narendra Modi asked the defence ministry to ensure that the project was not derailed.

However, even after Modi’s intervention, there were issues such as additional cost and the army had objected to construction of entry and exit points of two stations in the Maidan area.

Sources said the railway ministry had written a letter on July 4 to Calcutta Metro, approving the additional cost.

“We are now planning to engage a general consultant and project management consultant as the first step. Work is expected to start soon,” said a railway official.

According to plans, there will be four underground stations, one each at Kidderpore, Victoria Memorial, Park Street and Esplanade. At Esplanade, there will be integration of three routes, existing north-south Metro, East-West Metro and Joka-Esplanade Metro.

The tracks will be built about 20 metres underground. “The tunnels will be bigger than that of East-West because Joka-Esplanade is broad gauge line,” said an official. He said tunnel boring machines would be used for the construction.

Last year, the defence ministry had ended the stand-off that had prevented the Metro corridor from having entry and exit points overground for two proposed underground stations on the Maidan side.

The army had refused permission to Metro to create passages through which commuters could enter and exit the underground Victoria Memorial and Park Street stations.

The breakthrough came after multiple meetings initiated by the state government.

Work on the 16km corridor had started in July 2011, but the project soon ran into land logjams. Rail Vikas Nigam Ltd, the implementing agency, has split the project into two phases.