The Australian Taxation Office yesterday couldn't answer exactly how many stapling-triggered employer checks it expects, but maintained its readiness for a July 1 go-live.

The $59 billion industry fund is calling on the government to include all superannuation products in the proposed performance benchmarks from the same date and not commence the rest of the measures until all underperforming funds have been removed from the system.

Australia's largest superannuation fund is taking issue with the proposed stapling regulations, arguing that the model is backwards and will not protect members from being stuck in dud funds.

Appearing before the Senate Economics Legislation Committee this morning, Mercer implored the government to consider a delay to the implementation of the super fund stapling mechanism slated to come into effect from July 1.