During the first phase of implementation of a PEI programme, the core of the PEI programme is to influence and mainstream environment into policy processes, at national, sector and local level. 

In practice, this means performing integrated policy assessments on the inclusion of environment sustainability into the policies (such as Strategic Environment Assessments), raising-awareness, identifying priorities and objectives, and mainstreaming environment into the policy documents.
A number of reviews, methodologies, tools and examples from countries can be used as reference.

Reviews and introductory documents

• Environment and climate mainstreaming: challenges and successes, Emily Benson, Alex Forbes, Mika Korkeakoski, Razi Latif & Dechen Lham, 2014 
• The challenges of environmental mainstreaming: Experience of integrating environment into development institutions and decisions, Barry Dalal-Clayton and Steve Bass, IIED, 2009
• Integrated Policymaking for Sustainable Development, A Reference Manual, UNEP, August 2009
• Environmental Health Issues in Poverty Reduction Strategies: A Review, Environment Strategy Papers No. 12, World Bank, September 2006
• Strategic Environmental Assessment: A Sourcebook and Reference Guide Based on International Experience, IIED, 2004
• Environment in Poverty Reduction Strategies and Poverty Reduction Support Credits, World Bank, November 2004
• Poverty Reduction Strategies and the Millennium Development Goal on Environmental Sustainability: Opportunities for Alignment, Environmental Economics Series, Paper No. 92, World Bank, September 2003
• Integrating the Rio Convention into Development Co-operation, OECD, 2002

Methodologies and tools

• Strategic Environmental Assessment Toolkit, World Bank
• Mainstreaming Poverty-Environment Linkages into Development Planning: a Handbook for Practitioners, 2009, UNDP-UNEP Poverty-Environment Initiative, English, Français, Español, Português, Русский
• UNEP, Mainstreaming Sustainable Consumption and Production and Resource Efficiency into Development Planning, 2009 [English] [Francais] [Español]
• UNEP, Issue Brief: Incorporating SCP and RE in Development Planning When Mainstreaming Poverty-Environment Issues, 2009
• Integrated Assessment: Mainstreaming Sustainability into Policymaking: A Guidance Manual, UNEP, August 2009
• Making Mainstreaming Work: An Analytical Framework, Guidelines and Checklist for the Mainstreaming of Marine and Coastal Issues into National Planning and Budgetary Processes, John Soussan, Stockholm Environment Institute, 2007
• Applying Strategic Environmental Assessment, Good Practice Guidance for Development Co-operation, DAC Guidelines and Reference Series, OECD, 2006 [English]
• Integrating Sustainable Consumption and Production into Poverty Reduction Strategy Papers, UNEP, Wuppertal Institute, 2006
• Integrating the Environment into the Poverty Reduction Strategy Papers, A methodology for evaluating a country’s perception of its performance, Anantha K. Duraiappah and Pumulo Roddy, IISD, June 2005
• Developing and Testing a PRSP Evaluation Methodology, Pradeep Tharakan, Mia MacDonald, WWF, November 2004

Examples from countries

• Rwanda Economic and Poverty Reduction Strategy, 2013-2018
• Five-Year Strategic Plan for the Environment and Natural Resources sector (2009 – 2013), Republic of Rwanda, 2009 [Policy brief:Agriculture and Development] [Policy brief: Environment and Economic Growth]
• ​Guidelines for Mainstreaming Environment in the Economic Development and Poverty Reduction Strategy, UNDP-UNEP PEI, Republic of Rwanda, 2007
• Poverty-environment-energy linkages in Rwanda, 2006
• ​Mainstreaming environment in energy strategies to address poverty in Rwanda, 2006
• Guidelines for Mainstreaming Environment in Policies and Programmes, Royal Government of Bhutan, 2010
• Process of Developing a National Environment Policy for Kenya, 2007
• Manual de Planificação, República de Moçambique, PEI, 2009
• Análise do PES e das Políticas Sectoriais, PEI Mozambique, 2009
• Poverty and Environment Issues: Governance Institutions, Institutional Frameworks and Opportunities for Communities, PEI/WWF, 2006
• Participacao comunitaria na gestao dos problemas ambientais locais: Experiências das Comunidades Locais de Maganja da Costa e Madal, Zambézia, 200
• The Agriculture Sector Wide Approach, Malawi’s prioritised and harmonised Agricultural Development Agenda, Ministry of Agriculture and Food Security, Republic of Malawi, 2009
• The Agriculture Sector Wide Approach Results Framework, Malawi’s prioritised and harmonised Agricultural Development Agenda, 2009
• Etude sur les modes de consommation et de production durables au Mali, Mali, 2010
• Evaluation Environnementale Stratégique du secteur du Développement Rural, Republique Islamique de Mauritanie/IPE, 2010
• Analyse de l’ntegration de l’environnement dans le politiques sectorielles en Mauritanie, Republique Islamique de Mauritanie/IPE, 2010
• Analyse de l’intégration de l’environnement dans les Politiques Publiques en Mauritanie, Ministère délégué a l’environnement (RIM), PEI, 2007
• Environment and Natural Resources Report Series: Enhancing Wildlife’s Contribution to Growth, Employment and Prosperity, PEI Uganda, 2009,
• Environment and Natural Resources Report Series: Enhancing Wetlands’ Contribution to Growth, Employment and Prosperity, PEI Uganda, 2009
• Environment and Natural Resources Report Series: Enhancing Forests’ Contribution to Growth, Employment and Prosperity, PEI Uganda, 2009
• Environment and Natural Resources Report Series: Enhancing the Contribution of Weather, Climate and Climate Change to Growth, Employment and Prosperity, PEI Uganda, 2009
• Review of the Existing Poverty Reduction Policies, Plans, Programmes and Projects for their Adequacy in Addressing Environmental Concerns, Uganda National Environmental Management Authority, Sustainable Development Centre, 2005
• Environment at the Heart of Tanzania’s Development: Lessons from Tanzania’s National Strategy for Growth and Reduction of Poverty – MKUKUTA”, IIED, 2007