The treaty does not include the term „non-governmental organization”. References to problems relating to the third sector are included in articles 138 and 139 of the Treaty devoted to social dialogue, and Article 257, establishing the Economic and Social Committee. Article 257 of the Treaty, amended by the Nice Treaty, states that the Committee is composed of representatives of various economic and social groups within the organized civil society.

Additionally, problems of the third sector are mentioned by two declarations: no 23, on cooperation with charities attached to the Treaty of Maastricht, and declaration no. 38 on volunteer activity attached to the Treaty of Amsterdam. 

Basic documents concerning non-governmental organizations issued by the European Committee include: 

• "Promoting the role of Voluntary organizations and Foundations in Europe" COM/97/0241 final, and
  
• "The Commission and non-governmental organizations: building a stronger partnership" COM (2000)11 final, January 18, 2000)

The question of non-governmental organizations and their role in building civil society has been also touched in the White Paper on European Governance (COM (2001) 428 final).  

The Convent and the third sector

In February, 2002, following the summit of the Convent, four European NGO networks and the European Trade Union Committee(ETUC)  formed the Civil Society Contact Group. The group prepared opinions on the issues discussed by the Convent. Meetings of the Convent are observed by representatives of the trade unions and employers’ organizations. NGO representatives influenced works of the Convent through Convent Forum. Opinions of civil society organizations on issues discussed by the Convent and on regulations included in draft of the Treaty were published at the online Forum.   

• Discussions on the state level;
  
• Work of the eight contact groups dealing with separate areas of NGO activities (“social issues”, “ecology”, “expert groups”, ”citizens and institutions”, “local and regional authorities”, “human rights”, “development”, “culture”);
  
• Plenary session of the Convent

A session devoted to problems of civil society was held on June 24-25, 2002.

European Networks
Networks demonstrate self-organization of the NGO sector on the European level. They link NGOs operating within certain sectors and represent them towards EU institutions. One of the most resilient NGO networks is the Platform of European Social NGOs. 
In June 2001, the representation of Polish NGOs was established in Brussels.