A needle and syringe program at the Alexander Maconochie Centre was part of an agreement struck by Labor and the Greens on forming a minority government after the 2012 ACT election.

However, attempts by the government to put the plan in place have stalled in the face of fierce opposition from prison guards and their union, the CPSU.

Corrections Minister Shane Rattenbury said both Labor and the Greens continued to stand behind their plan, saying it was addressing a public health issue.

But the Liberals' Andrew Wall called on the ACT government to abandon the program in the Legislative Assembly on Wednesday, saying the government had failed to consider guards' views.

"The ACT should not continually be called upon to be the crash test dummies for ideologically driven policy, or for policy that is at the behest of the solitary ACT Green, balance of power holder," he said.

The opposition's motion was defeated by a vote of nine to eight, but Mr Wall said it would not be the end of their campaign over the issue.

"There'll be continued motions in Parliament, further questions, scrutiny and a public campaign into the future, calling for this to be abandoned," he said.

CPSU secretary Vince McDevitt said he regretted common sense had not prevailed on the floor of the assembly on Wednesday.

He said his members continued to express their disbelief at government policy.

He said he believed the program was dangerous and encouraged drug use in Canberra's prisons.

"[Prisoners] are not going to get rehabilitated off drugs while the government is facilitating their habit. This is a ridiculous proposition and the reality of the policy [is clear] when you just stand back and look at it," he said.

Mr McDevitt said the union met Mr Rattenbury on October 2 to try and find a way forward.

Mr Rattenbury said the program provided clear public health benefits not just for the prison population at the Alexander Maconochie Centre, but also for the ACT in general.

Despite lengthy negotiations with the CPSU, Mr Rattenbury said he was optimistic there was goodwill to keep working constructively.

"It is disappointing that it has taken this long to make progress but I remain committed to working with Corrective Services officers to find a way through this to build a model that is practical and works in the prison environment," he said.

He said rather than encouraging drug use in the prison, the ACT government was tackling the problem in several ways.

"I'm very committed to the three-pronged strategy of supply reduction, demand reduction and harm minimisation, which means we need to do what we can to keep drugs out of the jail, to help people in jail break the habit and also to acknowledge that, in the real world, prisoners do drugs and we need to make sure [to] minimise the risk arising from that," he said.