Changes made to sports grants decisions without the knowledge of former minister Bridget McKenzie are "alarming," a constitutional expert has said.
Professor Anne Twomey told a Senate inquiry on Thursday she believed Senator McKenzie didn't have authority under the constitution to make decisions about the $100 million sports grants program in the first place, and the government hadn't yet proved the power exists.
"So far, the Commonwealth has not identified the sources of constitutional power it claims to support this scheme. It seems to be relying on what is called an assessment of constitutional risk," Professor Twomey said.
It appeared the Commonwealth government went ahead with the scheme under the assumption it wouldn't be challenged in court, she said.
"Deliberately breaching the constitution or not caring whether you breach it or not, as long as the outcome is to your advantage and you are not caught, is not setting a good example to Australian citizens and especially to young people.
"It breeds contempt and disengagement from our political system."
Professor Twomey criticised the government's handling of the issue, including that it appeared decisions were made without the minister's knowledge.
"I think any minister would want to make sure they are aware of such things and sign the final document which allocated those kinds of grants."
Making decisions on where sports grants were approved based on political considerations would also not be allowed under the Act governing Sport Australia, Professor Twomey said.
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Nationals senator Matt Canavan raised the prospect of the government being given authority by passing the budget appropriations bill.
But Professor Twomey shot down the idea.
She also said money for sporting clubs should be handed out through state and local governments.
Professor Twomey questioned if any senators could seriously say the framers of the constitution envisaged sporting clubs getting federal money.
"Frankly it's madness and no sane person would devise such a system. Certainly those who wrote the constitution were sane and did not devise such a system."
Prof Twomey said it was of great concern if ministers believed they had unlimited discretion over public funds.
"They cannot rely on ignorance of the law for their exculpation," she said.
- with AAP