A survey of 50 employers by the department, representing 1.9m workers, found that the average opt-out rate for workplace pensions measured 9 per cent between October 2012 and April 2013.
Opt-out numbers related to employees who left their pension schemes within a month of the date they were automatically enrolled.
Data revealed that overall participation in a workplace pension grew from 61 per cent to 83 per cent, with opt-out rates ranging from 5 per cent and 15 per cent.
Participation rates also rose for employers who had previously used contractual auto-enrolment programmes, from 90 per cent to 96 per cent in statutory schemes.
Pensions minister Steve Webb, who was encouraged by the statistics, said: “Seeing our largest employers report such low opt-out rates bodes well for this ambitious programme, which will see millions more putting money aside for the future.”
However, Glynn Jones, divisional director of group savings and investment at national pension consultants LEBC Group, warned that more needed to be done to bridge the savings gap.
He said: “If we are swapping savings into pensions from, for example Isas, and there is no upswing in people preparing properly for life beyond retirement, then the auto-enrolment project will have failed.”
Independent pensions consultant Ros Altmann added: “Obviously, this is encouraging, but we shouldn’t get too carried away.
“Smaller firms are less likely to be as enthusiastic, especially those that have not offered pensions before. They are unlikely to be so willing or able to devote such resources to auto-enrolment.”
Participation with contractual enrolment
Before AE: 90%
After AE: 96%
Participation without contractual enrolment
Before AE: 36%
After AE: 71%
Tom McPhail, head of pensions research at Bristol-based Hargreaves Lansdown, warned that greater challenges were ahead, particularly with increasing contribution rates, and maintaining high participation among smaller employers. He said: “The largest employers were always likely to produce the best results. By the end of 2014 we’ll have a much better idea of whether we really are getting to grips with the pensions crisis.”