In April 2017, the government began creating Contractor Central, a centralised, whole of government contract awarded to labour-hire firm Comensura to recruit contractors for all territory departments, in a bid to save the government about $2 million a year.

But the new arrangement has cost the government $74 million in contractors, on top of labour hire fees to Comensura worth at least $2 million a year, overspending its budget. The government has refused to detail the budget or the overspend.

The rising government spending on the centrally contracted workforce comes despite moving to a flat rate on procurement, as well as setting a flat margin for the contract workers, in a bid to cut the costs of contracting workers.

There has also been some standardisation of pay rates for new hires, benchmarked to improve consistency in pay rates for contracted workers performing similar activities.

Figures released through an answer to a Legislative Assembly question on notice posed by Opposition leader Alistair Coe show the government spent $7.2 million on its centralised contract workforce in from April to June 2017, when it first began operating.

But that figure ballooned to $46 million in 2017-18, as more contract workers were transferred from other agencies into the scheme, and then fell to $21 million in 2018-19, totalling $74 million spent since the program began.

The most common jobs the government has sourced through the new system were call centre operators, gardeners, IT support staff and project coordinators.

Those figures do not provide the complete picture, however, with agencies and territory directorates still able to employ contract labour directly, but the government could not provide whole of government figures to show whether, in total, contracted labour was rising or not.

But in an answer to a Question on Notice, the government wrote that it had identified trends since Contractor Central had started operating that "there has been a small increase on contract spend since implementation".

A spokesman did say that the average monthly spend on contractors through the program had risen from $2.4 million across five agencies in 2016-17 to $3.8 million across 22 entities in 2017-18 and $5.2 million in 2018-19.

Over the same period, documents tabled in the Assembly show, the number of contractors rose from 267 in 2016-17 to 937 in 2017-18 and down to 651 last fiscal year, the vast majority working in Shared Services, Transport Canberra and City Services, Access Canberra and ACT Health.

The spokesman said in a statement monthly figures were variable and full year figures provided a better comparison, but despite having operated the new system since August 2016.

"As contingent labour is often seasonal in nature, and consequently variable from month to month, whole of year spend data would provide a better comparison for trend analysis than numbers extrapolated from part year data (the period April 2017 to October 2018)."

"Over time, Contractor Central will provide better whole of government analysis to enable the best arrangements for labour engagement across the ACT Government," he said.