As a movement for social reform SAK also influences political policymaking and public opinion.

SAK represents the interests of over 900,000 members in 18 affiliated trade unions. This makes SAK the largest lobbying organisation in Finland.

SAK is a confederation of 18 trade unions in industry, the public sector, transport, private services and culture. These unions have a total of almost one million members, and promoting the emotional and material welfare of these individuals is the prime concern of SAK.

Membership numbers of SAK-affiliated trade unions of 1 January, 2018