Figures from the 2014 occupational pension scheme survey highlight the contradictory messages about the introduction of automatic enrolment.

The good news is that the number of members in occupational pension schemes soared from 8.1 million in 2013 to 10.2 million in 2014.

This is largely because the number in private sector occupational defined contribution schemes increased by two million and is likely to be almost entirely due to automatic enrolment.

But the data greatly underestimates the impact of automatic enrolment on pension scheme membership. Many people joined group personal pension schemes that are not counted by the ONS survey. Many more joined schemes as a result of automatic enrolment after the survey was done.

The bad news is that the average contribution rate to private sector occupational defined contribution schemes plummeted from 9.1% of pay in 2013 to 4.7% in 2014.

Some commentators have speculated that this fall was in part due to a “levelling down” in the contribution rate enjoyed by existing members of such schemes.

But Prospect’s anecdotal experience does not back this up. The statistics suggest that the millions of extra pension scheme members are mostly receiving contributions at the minimum level required under automatic enrolment.

Prospect’s pension officer, Neil Walsh said: “We are in danger of swapping a problem of too many people in no pension scheme for one of too many people in a poor pension scheme.

“Prospect’s analysis shows that the minimum levels of contribution under automatic enrolment will not provide an adequate level of income in retirement for a median earner.

“We need an independent commission to assess the level of contributions required to provide a decent standard of living in retirement and to make recommendations to government about the minimum levels of contribution under automatic enrolment.”

Prospect would also like the proposed commission to review the impact of automatic enrolment on the gender pension gap. A recent report from the Pension Policy Institute showed that women were over-represented among the population ineligible for automatic enrolment.

Walsh added: “Government policy should focus on reducing the gender pension gap. The earnings trigger and other elements of automatic enrolment need to be reviewed if they are shown to be exacerbating this problem.”