AGMA had a constitution and committee structure, with the leaders of the ten district councils meeting regularly at its head to develop county-wide policies and services.

[2] The local authorities of Blackpool, Blackburn with Darwen, Cheshire East and Warrington were associate members with representation at AGMA debates and meetings, but were excluded from voting processes.

The Greater Manchester Council for Voluntary Service had been instrumental in lobbying to strengthen the powers of Section 48 of the Local Government Act 1985 when it was still being debated as a Bill in the House of Lords.

During its 25 years of operations AGMA made representations on behalf of Greater Manchester to the government of the United Kingdom, the North West Development Agency, the European Union,[5][6] business and other bodies, lobbying for investment and funding.

Under its constitution (passed in 2008), the Executive Board of AGMA coordinated economic development, housing, planning, and together with the relevant statutory bodies, transport policies for Greater Manchester with a supporting structure of seven commissions.

[9] As at January 2010, six commissions were in operation, being:[10] Following a bid from AGMA highlighting the potential benefits in combatting the Great Recession, it was announced in the 2009 United Kingdom Budget that Greater Manchester and the Leeds City Region would be awarded Statutory City Region Pilot status, allowing (if they desired) for their constituent district councils to pool resources and become statutory Combined Authorities with powers comparable to the Greater London Authority.

[13] The Local Democracy, Economic Development and Construction Act 2009 enabled the creation of a Combined Authority for Greater Manchester with devolved powers on public transport, skills, housing, regeneration, waste management, carbon neutrality and planning permission, pending approval from the ten councils.