Greater detail is needed on how the federal opposition will support the increase in the superannuation guarantee (SG) levy, Employment Participation and Childcare Minister Kate Ellis has said.

Last week, the coalition announced it would support the SG increase  to 12 per cent despite its previous commitment to keep the levy at 9 per cent.

"It seems to me that the coalition is picking all the positive bits of the government's SG package and ignoring the hard decisions, such as how to fund the increase," Ellis told a Women in Super lunch in Sydney on Monday.

The mining tax played a crucial role in funding the government's SG package, but to date the opposition had provided "no details" on how it would fund its package, she said.

She also called on the coalition to confirm whether it would keep the government's proposed low-income superannuation government contribution.

Under the government's measure, the 15 per cent tax on superannuation will be abolished for people earning up to $37,000. The measure is part of the Super Guarantee (Administration) Amendment Bill, which was introduced into Parliament last week.

The draft policy is expected to deliver up to $500 a year extra in superannuation for people earning less than $37,000.

Australian Institute of Superannuation Trustees chief executive Fiona Reynolds said the proposed low-income superannuation government contribution was an important equity measure.

"That sort of saving is going to make a big difference to those who might otherwise struggle in retirement," Reynolds said.

"Importantly, individuals do not need to make any extra contributions to benefit from this measure. It will be of great value, not only to many full-time workers, but also to part-timers and women who take career breaks to raise children."