The STOP67 campaign is calling for legislation introduced in 2011, allowing for the increase in the pension age to 67, to be removed immediately from the statute books.
The campaign includes SIPTU, the National Women's Council of Ireland, Age Action and Active Retirement Ireland.
It said the legislation needs to be removed in order to allow for a "representative" and "democratic" process of consultation, and for the proposed Commission to complete its work.
The programme for Government included a commitment to defer the increase to 67, due to come into force on January 1, 2021, "pending the report of the Commission on Pensions and any subsequent Government decisions on its recommendations."
SIPTU Deputy General Secretary, Ethel Buckley, said: "We believe that the membership of the Commission should genuinely reflect the interests of all stakeholders in order to achieve the consensus required from all sections of society on the pensions issue.
"Participants should have equal access to all data, information and the models (demographic and public finance projections, cost and savings of various measures, etc.) to be used in the work of the Commission in order to ensure authentic shareholder engagement," she said.