Department of Social Services, Services Australia, National Disability Insurance Agency, NDIS Quality and Safeguards Commission officials will present evidence to the select committee on COVID-19 on Thursday..

Almost 600,000 businesses have applied for the JobKeeper wage subsidy - a payment of $1500 a fortnight - to support more than 3.3 million workers.

The figure is well under the estimated six million workers over a six-month period when the policy was costed at $130 billion.

In addition, the government has doubled the JobSeeker payment - formerly known as Newstart - and expanded eligibility to income support for the period of the coronavirus pandemic.

Labor has concerns about what will happen when the pandemic is contained and the extra payments are withdrawn.

Prime Minister Scott Morrison says the emergency measures have a set lifespan and a wind back will be needed to ensure the federal budget does not blow out further.

"Labor has serious concerns about the impact this will have on the hundreds of thousands of Australians whose jobs remain uncertain, and the impact this will have on the economy when or if the government suddenly snaps back the payment," Labor senator Katy Gallagher said.

Another committee is due to report on Thursday afternoon on the adequacy of income support and related payments.

The Senate committee began its work in July last year and has received hundreds of submissions, many of which are critical of the low level of payments.

The report is expected to look at what constitutes an acceptable standard of living in Australia, the structural causes of long-term unemployment, and the changing nature of work in Australia.

AAP