That would mean more than $60 million is being poured into the ACT economy every two weeks via the payment.

Labor leader Anthony Albanese called for clarity on the future of the program.

"Mr Morrison has already excluded more than a million Australians from JobKeeper. He must not make things even worse for Australian families and businesses by withdrawing support too soon," he said.

The wage subsidy is worth $1500 a fortnight and is being paid to 3.3 million workers in 872,000 businesses around the country. Treasury figures show 10,700 Canberra businesses are using the subsidy to pay their staff. Based on an average of 3.8 workers per company in the scheme, Labor calculates that 40,500 Canberrans are on the payment.

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Canberra has slightly fewer businesses on JobKeeper than its population share, no doubt due to the high proportion of government employees.

The wage subsidy, costing $60 billion over six months, is due to end at the end of September. The government is considering a Treasury review, with a new set of stimulus and support measures to be announced on July 23, when Treasurer Josh Frydenberg delivers a budget update.

It is possible some changes will take effect before the end of September - and much has been made of the people who got a pay boost under JobKeeper. For many part-timers and casuals, the flat payment of $750 a week meant a pay increase - and a sizeable one for people only working a couple of shifts a week.

Economists have called for the scheme to be phased out over the rest of the year rather than cut off at the end of September, warning of an economic cliff if support is cut suddenly.

A sizeable number of people on JobKeeper are getting no work at all, with May figures from the Australian Bureau of Statistics showing 750,000 people were technically still in work but had zero hours of work. They would be expected to join the unemployment benefit if JobKeeper finished.

To qualify for the scheme, businesses had to have experienced a 30 per cent reduction in turnover in March, and some economists have suggested a new turnover test which would exclude businesses where their turnover has improved again since March.

The government has talked about targeting its support to specific industries. This week, Mr Frydenberg said the new phase of income support would be "targeted, it will be temporary, it will be designed to get help to people who need it most".

Labor Treasury spokesman Jim Chalmers said the Victorian outbreak made it even more important to have clarity.

"The Morrison government could better target and taper it, but shouldn't just turn off the tap when businesses are struggling with new restrictions," he said.

Government figures show that 88 per cent of businesses on JobKeeper are "micro", with turnover of less than $2 million a year. Another 8 per cent are small to medium businesses, with turnover of $2 million to $250 million. Just over 1800 big businesses (2 per cent of the total) are on the wage subsidy.