Donald Trump has signed an executive order protecting production of glyphosate-based herbicides, such as Roundup, which some bodies and studies have linked to cancer and which are the subject of widespread US litigation.

The president’s move, which also seeks to provide “immunity” for makers of the herbicides, was strongly criticized by health and environmental advocates including some figures in the Make America Healthy Again (Maha) coalition.

The new order directs the Agriculture Secretary to consult with the Secretary of War to determine the materials, services, and facilities needed nationwide “to ensure a continued and adequate supply of elemental phosphorus and glyphosate-based herbicides.”

It also waives the liability of companies complying with the order and says that the Secretary of Agriculture will ensure “that any order, rule, or regulation issued under this section does not place the corporate viability of any domestic producer of elemental phosphorus or glyphosate-based herbicides at risk.”