Gurgaon: Four months after the Haryana government demarcated a large part of the Mangarbani groves as a 'no construction zone' in February this year, it has failed to come up with a gazette notification declaring Mangarbani and its buffer area as a protected 'forest'. Environmentalists on Sunday wrote a letter to the government, appealing it to issue the required notification at the earliest. Around 677 acre in Mangar (Faridabad) and Bandhwari (Gurgaon) were demarcated as 'bani', ie, the core area of the deemed forest, while 1,266 acre, which fall under the revenue villages of Mangar and Kot in Faridabad district and Bandhwari in Gurgaon district, were demarcated as its buffer zone. This made a total area of 1,943 acre outside the reach of construction activities. But the area is yet to be categorised as a preserved forest. Mangarbani is considered the last remaining virgin forest area in Delhi-NCR. The 'bani' is a block of forest area with dense tree cover, that falls under Mangar and Bandhwari villages. In the letter written to the DTCP principal secretary, the environmentalists have accused the government of dragging its feet over issuing the notification. The letter says the government should notify Mangarbani and its 500m buffer area, which has already been demarcated, as a no-construction zone in its official gazette, describing Mangarbani as a forest in the notification. The letter proposes an amendment to the sub-regional plan to reflect the delineated Mangarbani and its buffer, now increased to 500m, and to seek approval of the Union ministry of environment and forests and the NCRPB (NCR Planning Board) for the same. Vivek Kamboj of Haryali NGO said there are talks at various levels for many years to protect Mangarbani, but till now, no legal frameworks has been developed. "In the NCRPB meeting in June 2015, the chief minister had committed to protect Mangarbani and its buffer area of 500m as a no-construction zone. But even after 12 months, the government has failed to come up with the necessary notification," he said.