The Ad Hoc Preparatory Session of the ASEAN Environmental Rights Framework and the Interim Working Group (IWG) Meeting were held on November 22–23, 2022, in Bangkok, Thailand, to conclude the Working Group's Terms of Reference and discuss possible elements of the draft Regional Framework on Environmental Rights in ASEAN. Early in 2023, the ASEAN Intergovernmental Commission on Human Rights (AICHR) adopted the Terms of Reference of the ASEAN Environmental Rights Working Group (AER Working Group) following this preparatory session. The purpose of the AER Working Group was to develop a regional framework on environmental rights for further consideration by ASEAN Sectoral Bodies before eventual adoption by ASEAN leaders. The AER Working Group abides by the AICHR's Terms of Reference, the Phnom Penh Statement of the Adoption of the ASEAN Human Rights Declaration, and the ASEAN Human Rights Declaration's guiding principles. H.E. Professor Amara Pongsapich, Representative of Thailand to the AICHR, is the chair of the AER Working Group. The composition of the AER Working Group is indicated in its Terms of Reference. Its membership includes representatives of the AICHR, ASEAN Sectoral Bodies, civil society organisations, experts, and special advisors.

The purpose of the AER Working Group is to develop a regional framework on environmental rights, which will be submitted to AICHR for further discussion. AICHR will consult ASEAN Sectoral Bodies relevant to the environment, particularly the ASEAN Senior Officials on Environment (ASOEN), for consideration before eventual adoption by ASEAN leaders.