Four key industry bodies have taken an unprecedented step by joining together to call for the Cooper review to take another look at its recommendations.

The Association of Superannuation Funds of Australia, the Investment and Financial Services Association, the Australian Institute of Superannuation Trustees and the Corporate Superannuation Association do not want Cooper's proposed architectural model to be implemented.

In December 2009, Cooper recommended a choice architecture model as part of phase one of its review into superannuation.

"We believe the proposed model does not focus on the key issues of making the system more efficient, but seeks to fundamentally alter an existing structure that has served members well," a joint statement said.

The choice architecture model proposed universal and choice investment options for people depending on their level of engagement with superannuation.

The new model would have to establish separate fund structures to cater for the members categorised as either universal or choice, the four groups said.

"This would inevitably increase the administrative burden on the total fund, which would translate into higher, not lower costs per member," the group statement said.

"Requiring the separate trust structures, we believe, will erode the economies of scale that currently exist."

The model also fails to recognise that level of engagement is also a factor of age and stage of life, the groups said.

The groups also have "serious industry misgivings" about the lifecycle investment strategy proposed by the Cooper review.

"We believe that the existing system allows for trustees to focus not simply on costs, but also on returns for default options," the group statement said.