"What the Treasurer and I will announce this week will not commence the day after we announce it, it will be several months from then," Mr Morrison said on Monday.

"The support that has been in place since April will be in place until September, and then we'll move into a new phase."

The next package would be targeted, temporary and effective, he said.

The government has been signalling for some weeks that the wage subsidy will be reduced for casuals and part-timers who earned less than $1500 a fortnight before it began.

Treasurer Josh Frydenberg effectively confirmed that on Monday, saying one of the "modifications" to JobKeeper would reflect that disparity. The expectation is that casuals and part-timers will be put on a flat rate, but a lower rate.

JobKeeper is also expected to be targeted to specific businesses or industries still in trouble - perhaps through requiring businesses to demonstrate that their turnover is still down by a certain threshold.

At the moment, businesses qualified for the six-month JobKeeper wage subsidy if their March turnover was 30 per cent down on last March (or 50 per cent for big businesses), no matter whether turnover recovered in April or beyond.

Mr Morrison said businesses whose turnover was still down because of the pandemic and the restrictions on crowd sizes and movement would continue to get government support beyond September.

The government's biggest support to date is the JobKeeper wage subsidy, paying $1500 a fortnight to 3.3 million workers.

The JobSeeker unemployment benefit was also doubled, to $1100 a fortnight.

Both are due to end at the end of September.

The government has been paying half of the wages of apprentices, at a cost of $21,000 a year for each apprentice, and last week the government announced that subsidy would continue till March.

It is also giving tax incentives to businesses to invest and buy equipment and is guaranteeing business loans, with the loan scheme extended on Monday.

Mr Morrison said support for businesses and the economy would have to be "a series of phases and how many phases there are it's difficult to say because there are so many uncertainties associated with COVD-19".

Mr Frydenberg and Finance Minister Mathias Cormann will release a mini-budget on Thursday, July 23. Confirming it was already with the printers, Mr Frydenberg said it would be an extensive document, with economic forecasts for the coming years.

More to come