More than 80% of the welfare recipients who had their income support suspended under the controversial ParentsNext program were not at fault, new figures show.

After the Coalition expanded the national pre-employment scheme last year, about 75,000 people who get parenting payments – mostly single mothers – were for the first time required to attend meetings and undertake education, training, or parenting programs such as playgroup to keep their payments.

But critics of the program have repeatedly warned that many parents are struggling to meet their mutual obligations, which had previously only been imposed upon on those considered to be jobseekers, such as people on Newstart.

Now, figures released to the Greens senator Rachel Siewert this week reveal that although a large proportion of all ParentsNext participants had their payments suspended for failing to meet their mutual obligations, most were not at fault.

Of the 33,620 parents who had their income support temporarily cut off last financial year, only 4,868 did not have a “valid excuse” and were handed a “demerit point” by their job agency, the figures show. It means 85% had their payments suspended despite having a valid reason.

The initial suspension of payments is a mostly automated process a under new job seeker compliance regime introduced last year. The government argues that people who have their payments suspended do not necessarily miss a payment and that if they are delayed, recipients receive backpay.

But Siewert said the compliance regime of welfare suspensions and penalties should not be applied to those on the ParentsNext program, who can have children as young as six months old.

“It does depend on when the suspension applies, but … it’s not as if people have savings,” she said. “And so if you get a suspension, you don’t have any money. That directly impacts on a parent with children.

“When you put on top of that the fact that a whole lot of [the suspensions] are because the provider has stuffed up, people … basically have nothing to fall back on. People talk about having to go to Food Bank and not knowing whether they’re going to be able to feed their kids.”

In one case last year, a woman had her payments suspended because she was admitted to hospital while 33 weeks pregnant and could not report to Centrelink.

Participants have complained about first learning they had been placed on the program when their payments were suspended, while one mother told Guardian Australia she had their income support temporarily cut for taking her children to kindergarten rather than story time at the library.

Labor’s employment spokesman, Brendan O’Connor, said: “The government’s implementation of the ParentsNext program is deeply flawed, with evidence it is causing parents and their children great distress.”

But the employment minister, Michaelia Cash, said the government’s new welfare compliance that was introduced last year was “less punitive”.

She said financial penalties – where a person’s payments are docked or forfeited rather than just suspended and delayed – had reduced by 90% compared to the old rules, while attendance rates also increased.

“We know this because in the year following the implementation of the new TCF there was an approximate 90% reduction in financial penalties compared to the old framework, and the attendance rate at appointments improved to 75% (from 71% in the last year of the old framework).”

“Where participants have a legitimate reason for not meeting their mutual obligation, they can inform their provider ahead of time and they will not experience any suspension at all.”

Meanwhile, O’Connor also accused the government of selectively releasing data about welfare sanctions, while refusing to release the official quarterly data.

“Labor recently asked for the latest job seeker compliance data through a Freedom of Information request, and was denied access to any information, yet coincidently the latest data has ended up in media articles today,” he said.

O’Connor was referencing a Newscorp story which said participants in the Jobactive program had their payments suspended 2.36 million times last financial year. The data was not released publicly.

The government has failed to release the official welfare compliance statistics this year.

Last month, the Daily Telegraph reported data showing that 78% of participants in the Jobactive employment program had their payments suspended. The story prompted a much-maligned “dole bludger” segment on Sunrise.

Guardian Australia requested the data referenced by the minister as well as separate figures. It showed more than 120,000 welfare recipients who had their payments suspended were not at fault.