The proposals are contained in a joint statement from the Local Government Association and the trade unions Unison, Unite and GMB, set out in a series of documents also released today.

Prospect will be discussing with branches the detail of the proposals which have been the subject of months of negotiations. The LGPS is different to most other schemes in the public sector as it is a funded scheme with an average contribution rate of 6.5%.

However, most of the changes – such as the moves to a career average scheme, CPI indexation and a full pension at state pension age – parallel those in other public sector schemes, including the civil service. An important difference is that the new proposals would take effect from April 2014.

Prospect members covered by the LGPS include those in the recently established Aspect group of members in education and children's services, the Environment Agency and a number of non-departmental public bodies.

Dai Hudd, Prospect deputy general secretary, said a meeting of branches will be called for late June to consider a recommendation on the proposals. A ballot of members would then be held in July-August.

"While this is not ideal, the timescale is dictated by the need to deliver a response to the Department for Communities and Local Government by the beginning of September."

A circular to branches affected by the proposals will be issued today.