Government claims welfare cuts will get parents back to work

Half a million single parents and stay-at-home parents could lose thousands of dollars in benefits under the federal government's tough budget cuts.

David Leyonhjelm is one of the few Senate crossbenchers who supports scrapping Family Tax Benefit part B.

"Not because I particularly like them but because they're savings," he said.

However Mr Leyonhjelm does not think his Upper House colleagues are as forthcoming.

"My understanding is that Senator Bob Day and Senator John Madigan are more concerned about single mothers and the fact that single income families are taxed more heavily," he said.

From July 2017, families stand to lose $3000 a year under plans to stop FTB part B when the youngest child turns six.

The move would save the government $8.5 billion.

With the cuts stuck in the Senate, Social Services Minister Scott Morrison could be looking to soften his stance, including raising the cut-off age from six to 12 years old.

"The government has signalled to us they're willing to negotiate about the age of the child," Mr Leyonhjelm said.

Mr Morrison has defended the cuts to Family Tax Benefit payments, and argued parents want help to get back into work. That will come from the $3.5 billion childcare package.

The government requires support from six of the eight crossbenchers to back their budget plan.

One of those crossbenchers is Family First Senator Bob Day, who said someone needs to go into bat for single-income families, and the focus should be on families raising children, not an increase to spending on childcare.