A group of more than 300 Iranian university professors, scholars, and environmentalists has written to Iran’s Supreme Leader opposing a petrochemical project scheduled for northern Iran.

In a letter published Thursday, they asked Ali Khamenei to intervene and stop the petrochemical plant near the Miankaleh wetland, Mazandaran province, which they say will have adverse environmental impacts on the coastal region. Politicians supporting the plant − which will convert natural gas to propylene, which has a range of uses in manufacturing − say it would create 75,000 jobs, but offer no evidence.

The environmentalists’ letter argued Iran already had sufficient propylene, and that a similar project in northern Iran begun by the Golestan Petrochemical company 17 years ago was in limbo although local ranches had been destroyed. The letter alleged there were around 90 abandoned petrochemical projects across the country, for which 40 construction permits had been issued under the previous government of President Hassan Rouhani.

They added that the area earmarked for the petrochemical unit in Miankaleh was high-quality agricultural land and was near to an international Unesco biosphere reserve. The environmentalists said that some work on the site – opponents of the development Tuesday cited welding for fencing and other preparations – was going on despite this week’s orders from President Ebrahim Raisi and the supreme court to pause or halt construction.