It was supposed to have happened by now. In the days following the inconclusive 2010 election, Julia Gillard promised a referendum to correct the silence about the First Australians in the nation's founding document. As part of the agreements she struck with independent MP Rob Oakeshott and the Greens for their support for her minority government, she committed to a referendum on indigenous constitutional recognition by the 2013 election.

An expert panel of indigenous leaders, lawyers and politicians delivered proposals to Gillard in January 2012, but progress stalled.

In September that year, Labor announced it would delay the referendum because of concerns that public awareness of the issue was too low.

No one thought it would be easy. Of 44 referendum proposals put since federation, only eight have succeeded in attracting the double majority required for constitutional change - an overall majority of Australians, as well as a majority in a majority of states.

But the task has proved more difficult than anyone imagined, both for Prime Minister Tony Abbott and for his predecessor.

Abbott went to the 2013 election promising to release a draft proposal for constitutional change within 12 months of taking office. This deadline passed in September with some progress, but no settled proposal.

Aboriginal and Torres Strait Islander Social Justice Commissioner Mick Gooda says despite much effort, the nation is no closer to a referendum than it was four years ago, when he was appointed to the Gillard government's expert panel.

"We risk squandering all the goodwill, as well as the momentum, by delaying a vote for too long," he says.

Tanya Hosch, the joint campaign director for Recognise, says she wants to see progress on finalising a model.

"No one can afford for this to drift … it's time to get on with it," she says.

Recently, the hard work of forging consensus on a form of words has fallen to a parliamentary committee led by Liberal MP Ken Wyatt and Labor Senator Nova Peris.

Perhaps their most difficult task has been to develop agreement on the Gillard government expert panel's proposal for a clause prohibiting racial discrimination.

While many Aboriginal people equate racial discrimination protection with recognition that is "substantive" as opposed to merely symbolic, it is unpopular with conservatives, who argue such a clause would expose legislation to excessive judicial review.

As opposition leader, Abbott expressed misgivings about the idea, fearing it "might turn out to be a one-clause bill of rights".

In late October, Wyatt's committee tabled a progress report which suggested three options. One was a broad ban on racial discrimination like that proposed by the expert panel. A second option provided a protection for indigenous people against adverse discrimination in the context of a section giving parliament power to make laws with respect to Aboriginal and Torres Strait Islander peoples. A third provides such a power without any reference to discrimination.

Speaking in December, Abbott said he believed the first two options would subject too much legislation to judicial review, while the third option would not do enough to recognise indigenous people.

Labor is supportive of a racial discrimination ban. Opposition Leader Bill Shorten told the same dinner Abbott addressed: "I believe that the view of the great and generous silent majority of Australians is there is no home for discrimination in our constitution, and we should not be rejecting this ambition out of hand."

Reconciliation Australia co-chair Tom Calma says he is heartened by the community backlash which last year convinced the Abbott government to abandon plans to water down racial vilification laws. "They were quashed by the community who said that we want to have protections because we want to address racism and discrimination."

But Calma suggests the referendum proposal be structured in such a way that gives voters options to support recognition, with or without new discrimination protections.

Kirstie Parker, the co-chair of the National Congress of Australia's First Peoples says swift finalisation of a model is crucial but urges leaders against "aiming too low."

"I think our country is potentially brave enough to be ambitious," she says.

But she says the Abbott government's changes in indigenous affairs, including its withdrawal of funding for basic services to remote communities, were complicating efforts to build support for recognition among Aboriginal people.

Western Australian Premier Colin Barnett has said that as a result of the change, his government may close up to 150 of the state's remote indigenous communities.

"Threats to Aboriginal people and their very existence, like the potential closure of remote communities in Western Australia, when combined with large-scale budget cuts, chaotic administration of indigenous affairs and little meaningful attention being given to what are internationally recognised rights of indigenous peoples, will inevitably reduce the appetite of our people to engage in so-called nation building exercises like constitutional recognition and reform," Parker says.

"The government needs to demonstrate it is fair dinkum about a meaningful relationship with our peoples," she says.

A review of public support for recognition, commissioned by the Abbott government and released in September, warned awareness of the campaign was waning, having dropped from 42 per cent in 2013 to 34 per cent in 2014.

But polling conducted for the Recognise Campaign late last year found 63 per cent of Australians feel ready to vote on the issue, and of those who are ready, three-quarters are ready to vote yes for recognition.

The campaign benefited last year from the advocacy of AFL footballer Adam Goodes, who made constitutional recognition one of his priorities while Australian of the year. But the absence of an agreed model has hampered efforts to educate the public, and to determine how recognition might improve the lives of indigenous people.

Shorten told Recognise supporters in December they had been working with both hands tied behind their backs, because "without a concrete proposal, we cannot turn the national goodwill into meaningful momentum."

Amid calls for the announcement of a referendum date, Abbott in December nominated May 27, 2017 – the 50^th anniversary of the 1967 referendum, which gave the Commonwealth the power to make special laws for Aboriginal people and count them in population statistics – as "a richly symbolic time to complete our constitution."

But he has not committed to that date, arguing the success of the referendum was more important than timing.

The legislative act of recognition passed by parliament in 2013, an idea conceived when Labor decided it could not hold a referendum that year, will expire in March. It is expected to be extended to align with the likely timing of a referendum.

Abbott knows from his experience on the monarchist side of the 1999 referendum campaign  that even proposals with wide popular support can be derailed.

"I know that because I helped to defeat the republican cause that was overwhelmingly supported by the Labor Party, significantly supported by the Liberal Party, and backed by every big media outlet in this country," he said in December.

This time he will be making the case for change, and says he is prepared to "sweat blood" for the recognition cause.

Gooda says when Australians vote for recognition, as he is confident they eventually will, "it will finally settle the place where Aboriginal people belong in this country."

"That will change the country forever and it will change it for the better," he says.

"I think there'll be two votes happening. One is the non-indigenous people saying 'we understand you were here first,' and the indigenous people saying 'we understand you're not going anywhere, so welcome aboard'."