ACT Chief Minister Andrew Barr says Prime Minister Scott Morrison's refusal to release the findings of a review of the JobKeeper before voters in Eden-Monaro go to the polls on Saturday sends a message that something "sinister is at play".
Mr Morrison will receive a Treasury review of the wage subsidy scheme and other coronavirus stimulus payments on Monday.
However, the future of the scheme beyond September will not be laid out until July 23.
Mr Barr said it was clear JobKeeer would need to be extended beyond September for industries still impacted by coronavirus restrictions.
"The fact they're not indicating what they're going to do ahead of the byelection would leave people rightly worried that there's something quite sinister at play here," Mr Barr said.
"They've got the report, we've been talking about this in the national cabinet for months. Everyone knows the cliff that lies ahead of us, they really should put the right information to the community about what's going to happen on JobKeeper, on JobSeeker and indeed on broader industry support. That's as fundamental in Eden-Monaro as it is right across Australia."
Mr Barr also said it was "concerning" businesses which needed to make decisions going into the new financial year on July 1 were doing so without clarity on what support would be available.
"It is important that we get an answer on this because not only business but state and territory governments also need to do some further planning and thinking about the supports we're going to need to provide," Mr Barr said.
However, Mr Morrison said he would not rush into a decision.
"There are many moving parts in this. This is not a simple issue," Mr Morrison said.
"When you're burning through cash at a rate of almost $11 billion a month on JobKeeper, then obviously that's not something you can continue in that form forever and that's why the government is being very careful in the considerations we're having."
The fact they're not indicating what they're going to do ahead of the byelection would leave people rightly worried that there's something quite sinister at play here.Andrew Barr
Mr Barr also said calls to reform the GST reform ahead of the 20th anniversary its introduction of GST were unlikely to gain much traction.
NSW Treasurer Dominic Perrottet has argued for the goods and services tax to be expanded so states and territories could scrap payroll tax and motor vehicle registration fees.
However, Mr Barr said such a change was unlikely to happen.
"At this point, the discussion of the GST seems a little bit of a fantasy. I've watched 20 years of tax reform debate, I've been an active participant in tax reform for 15 years now, there's often a lot of talk but not much action," Mr Barr said.
"We'll see what comes of the NSW paper but past history tells me I don't think the GST is an area that's likely to be reformed.
"What could have happened and what should have happened during this period is the Commonwealth could have provided targeted assistance to states and territories to do what the ACT has done and that is to eliminate stamp duty on new builds. That would have been a much better way of investing money from the Commonwealth, through the states and territories into programs to eliminate stamp duty.
"I think there is goodwill for tax reform, but I'm not sure the GST is the place to start."
Mr Morrison also said it was premature to talk GST reform.
"What I'm focused on at the moment is the decisions the government has to make in relation to JobSeeker and JobKeeper and they're important decisions as we move to the next phase post September," Mr Morrison said.