Centre said that the conditions posed by Delhi government are against the Metro Rail Policy 2017.

The Centre has said it cannot accept AAP government's conditions on the Metro Phase-4 and asked it to review its decision to not execute the project until the Housing and Urban Affairs (HUA) Ministry revises its approval.

The AAP government had in April directed the Delhi Metro Rail Corporation (DMRC) not to begin the work on Phase-4 project till the HUA ministry revises its approval in tune with the AAP dispensation's proposal, a source said.

HUA Secretary Durga Shanker Mishra has written to Delhi Chief Secretary Vijay Kumar Dev asking him to review the AAP government's decision and lift the embargo on work on Phase-IV at the earliest in public interest, the source said.

While approving the Metro Phase-IV, the Delhi Cabinet had imposed two conditions -- 50-50 sharing of operational loss between the Delhi government and the Centre, and that the Delhi government will not bear any liability of repayment of loan given by the JICA, Japan International Cooperation Agency.

In the letter, Mr Mishra said the conditions posed by the Delhi government are against the norms laid down in the Metro Rail Policy 2017.

"Hence, there is no question of accepting the recommendations of GNCTD (Government of National Capital Territory of Delhi)...which has not been done for any other metro project," Mr Mishra said.

The move may trigger another round of tussle between the Arvind Kejriwal-led government and the BJP-led Centre, and thus delay the execution of Metro Phase-IV project in the city.

The Union cabinet had in March approved three of six corridors of the Metro Phase-4 approved by the AAP dispensation, sidelining the conditions imposed by the Delhi government while giving its nod to all six corridors.

The three corridors approved by the Union Cabinet are Mukundpur-Maujpur (12.54 km), Janakpuri West-R K Ashram (28.92 km) and Tughlakabad-Aerocity (20.20 km).

The other three corridors of phase-4 which have not been approved by the Centre are Rithala-Bawana-Narela, Inderlok-Indraprastha and Lajpat Nagar-Saket G Block.

The AAP government had objected to it, alleging that the Union government has made some "unilateral changes" in the project, without communicating any reasons.

According to the source, Mr Mishra wrote in the letter the "Delhi Metro Phase-IV has already been delayed by more than four years for want of approval by GNCTD.

"The directive of GNCTD to DMRC not to start the work of phase-4 will further jeopardise of expansion of Metro network in the capital and leave it devoid of its benefits apart from adding to cost and time overruns."

Mr Mishra also said it is not understood why the Delhi government has taken the stand that there cannot be any change in overall project cost and project cost of three priority corridors from what has been sanctioned by the AAP dispensation.