OPINION: The odds are fading on Australia voting next year to recognise Aboriginal peoples in the constitution.

However, a referendum may still occur on local government. A long-awaited High Court decision due tomorrow may bolster the case for constitutional change to ensure that the Commonwealth can continue to directly fund local roads, libraries and childcare centres.

Julia Gillard made a number of commitments after the 2010 election in return for the support of Green and independent members. One was to put proposals to recognise Aboriginal peoples and local government to referendums at or before the next federal election, which must be held by November 30 next year.

Last year, the government commissioned expert panels to report on the options for reform. They identified a set of viable, if contentious, changes. In the half year since, the government has yet to respond.

We are now almost at the point where it will be impossible to hold a referendum in 2013 with a realistic chance of success. Some believe we have already reached this point for the indigenous recognition proposal.

Australians should not be asked to vote on constitutional change at or near the next federal election. A referendum, however sound, could be drowned out by the negativity certain to dominate that poll.

This means that any referendum should be held in the first half of 2013, leaving the government less than 12 months to draft the bills for constitutional change, secure opposition support, have the bills debated and passed by Parliament and convince Australians to vote yes.

These steps typically occur over the course of a parliamentary term, not just over its final months.

The lack of time is a significant problem for the indigenous referendum. Australia's major parties support the idea in principle, but have not agreed on what form the change should take. No attempt has yet been made to bridge this gap.

The problems go deeper. Australia's last referendum, in 1999, demonstrated the power of the slogans ''vote no to the politicians' republic'' and ''don't know, vote no''. The same type of arguments could be recycled in a referendum next year.

The Aboriginal referendum was put on the national agenda by a high-level political deal, rather than as a result of a grassroots campaign. A people's movement, like the one under way for marriage equality, has yet to emerge.

The campaign to recognise Aboriginal people and to remove racially discriminatory clauses from the constitution is being built by Reconciliation Australia and the YouMeUnity movement, but is still in its infancy.

This referendum must enjoy public support from a broad coalition of Aborigines, businesses, unions, community organisations and politicians. Without this, the referendum will join the long list of failed attempts to change Australia's constitution.

Auspoll has also found that most Australians do not even know of the referendum. It reported that 39 per cent had some awareness, but an overwhelming majority even of this group said they knew little or nothing about the proposal.

Community ignorance leaves any referendum in the next 12 months open to rejection. Australia's long experience of referendums is that people will understandably reject a proposal that they do not understand and do not feel comfortable about.

In this light, it is not surprising that members of the government's expert panel and indigenous leaders have talked down the prospects of a referendum being held next year. They rightly accept that the referendum should not be run unless it has a strong prospect of success, and that this almost certainly requires a longer-term strategy.

On the other hand, the government's promised referendum on local government may still go ahead. It suffers from the same problems of tight timing and lack of community knowledge, but has political support at the federal level and the advantage of agreement on what change is required.

The Commonwealth has for many years directly funded local government, such as for infrastructure and the well-regarded Roads to Recovery scheme. The High Court's decision in the Pape case in 2009 cast significant doubt on whether this funding can continue.

The issue may re-emerge this week when the High Court hands down its decision on the schools chaplaincy program. That decision may add significant weight to the case that the constitution needs immediate repair to ensure ongoing, direct federal funding of local government.

It may be that Australia gets a referendum in 2013, but not the one that many people were expecting.

George Williams is a Professor of Law at UNSW.

This opinion piece first appeared in The Sydney Morning Herald.