The Commission of the European Union (EU) is required to consult various social partners when it wants to submit proposals in certain fields. Social dialogue occurs via the three main organizations representing the social partners at European level: the European Trade Union Confederation (ETUC), the Union of Industries of the European Community (UNICE) and the European Centre of Enterprises with Public Participation and of Enterprises of General Economic Interest (CEEP). The Commission's job is therefore to take all necessary steps to encourage and facilitate consultation with the social partners on the future development of Community action and on the content of any proposals on the European Union's social policy, which is essentially concerned with the labour market. A consultative assembly of economic and social partners in Europe was created as early as 1957 with the Treaty of Rome. Its role was to involve these various interest groups in building the common market. Its members are drawn from representatives of three categories: employers, workers and independent occupations. The Single European Act, which entered into force in 1987, and the Treaty on European Union (in force 1999) increased the number of areas in which this assembly, the Economic and Social Committee, must be consulted by the other institutions when they wish to introduce legislation in the social sphere. See: European Centre of Enterprises with Public Participation and of Enterprises of General Economic Interest (CEEP); European Trade Union Confederation (ETUC); Union of Industries of the European Community (UNICE); Social dialogue (EU); Social dialogue (ILO)