Social Development Minister Paula Bennett is prepared to say sorry for the release of private income details of two solo mothers this week.

Bennett says she will apologise to Natasha Fuller and Jennifer Johnston if a Privacy Act complaint, laid against both Bennett and a Social Development Ministry staff member and obtained by the Herald on Sunday, is upheld.

Privacy experts suggest there is a clear case of a breach.

Fuller has had her telephone lines disconnected, after threats and abuse on talkback, online message boards and blogs.

Bennett disclosed the women's incomes this week. She said they totalled $715 a week for Fuller, and $554 for Johnston.

The disclosure came after the Herald on Sunday quoted the pair criticising Bennett's decision to stop the Training Incentive Allowance (TIA) for solo parents doing tertiary level study.

Both women have three children, with additional health and childcare costs.

Other mothers who have written to the minister have told of fears they would be similarly outed.

In the complaint, Labour MP Charles Chauvel, a lawyer, says Fuller wants a full apology from Bennett citing "significant humiliation and distress" from the abuse that she and her ministry caused.

The ministry, meanwhile, says none of its rules were broken because its staffer was acting on Bennett's orders when accessing the women's private files.

Chauvel cites five breaches of the Privacy Act, in that Bennett failed to make sure information about the women was "complete, accurate and not misleading".

These included:

- Not telling the media about any child support the state received on behalf of Fuller's children, which meant taxpayers didn't pay her the amount Bennett said they did.

- That her release was calculated to mislead the public into believing Fuller got an excessive level of state support.

- That Fuller's income was not relevant to the issue Bennett was addressing - government policy on funding tertiary education.

Bennett said she relied on Privacy Commission guidelines when revealing the women's income, claiming they had given their "implied consent" by talking to the media in the first place.

TIA lobby group Handup said it welcomed the prospect of an apology for the women and hoped the complaint was a warning to other ministers.