There are still nearly two years to go until the state next goes to the polls, but yesterday might well go down as the day Annastacia Palaszczuk’s Labor government won itself the next Queensland election.

This was not achieved Paul Keating-style, with a searingly effective demolition of a showpiece opposition policy, or as John Howard might have done, by using unanticipated external events to wrest back an initiative that had long seemed lost, but through a dramatic and entirely unheralded change to the electoral system.

The minority Labor government appeared to be on the back foot yesterday as crossbenchers lined up with the opposition to support a bill to add four extra seats to the 89-member Parliament, thereby addressing their concerns about the level of rural and regional representation.

The passage of the bill loomed as an embarrassing demonstration of the government’s weakness, as the decisive vote in favour was to come from Cairns MP Rob Pyne, who last month quit the ALP to sit as an independent.

However, the smile was shortly wiped from the Liberal National Party’s collective dial when the government tacked on an amendment to abolish optional preferential voting, and again require that voters number every box on their ballot papers.

That sounded awfully good to the crossbenchers, who now stand to receive the overwhelming majority of the preferences of any major party candidate they succeed in outpolling.

Opposition members were less pleased, with one going so far as to say: “Today we have seen democracy die.”

It’s hard to know whether to be impressed by the government’s audacity, or appalled by its cynicism.

The very same Labor Party whose federal members vented outrage just a few weeks ago over the rushed process on Senate reform was now turning the state’s electoral system on its head without so much as the fig leaf of a consultation process.

It stands in very stark contrast to the way optional preferential voting was introduced after Wayne Goss led Labor to power in 1989, and set to work addressing the scandalous state of the electoral system bequeathed to it after the Joh Bjelke-Petersen years.

Among the measures taken was the establishment of the Electoral and Administrative Review Commission, in response to one of the principal recommendations of the Fitzgerald inquiry that lifted the lid on the state’s culture of political and police corruption.

The main concern of this body was to address the gerrymandering and malapportionment that are remembered as Bjelke-Petersen’s legacy, though he was by no means their sole author.

It was no doubt pleasing to the Labor government that this august and non-partisan body recommended following the example of New South Wales in abandoning the requirement that voters number every box.

With the Greens yet to establish themselves as the third force in Australian politics, and the Australian Democrats not much of a factor on the state scene, the main impact of compulsory preferential voting was in allowing Nationals and Liberal candidates to contest the same seats without splitting the vote and delivering victory to Labor — precisely the reason preferential voting was first introduced at federal level by a conservative government in 1918.

The optional preferential voting reform was not much commented on at that time, as it was seen as a low-order concern when compared with the concurrent introduction of “one vote, one value” electoral boundaries.

For the most part, voters continued to number every box, following a habit ingrained by long-established practice at both federal and state level.

But as the years went by, two factors caused optional preferential voting to take on ever greater significance.

One was the weakening of the major parties’ hold on voter loyalties, and the resulting increase in the number of seats being determined by preferences, or the absence thereof.

The other was a strategy increasingly employed by major parties of simplifying their messages by recommending supporters “just vote one”, as former Labor premier Peter Beattie did to devastating effect when the right-of-centre vote fractured amid the One Nation insurgency at the turn of the millennium.

This was dramatically illustrated when Labor returned to power last year, just three years after the rout administered to Anna Bligh’s government in 2012 reduced it to seven seats.

Otherwise accurate opinion polls failed to forecast this outcome, as it had not been anticipated how dramatically the hard-edged approach of Campbell Newman’s government was going to change the behaviour of minor party and independent voters.

At the previous two elections, Greens voters in particular were inclined to place a pox on both houses after more than a decade of Labor rule, with around two in five of their votes exhausting when preferences were allocated.

But in 2015, two in five suddenly became one in five, as left-of-centre voters found a determination to go the extra mile to see the back of Newman.

Now Labor is back in government, it has had good cause to fear that the swelling ranks of Greens voters might revert to type.

The point is well illustrated by published opinion polls, which have recorded little change on the election result so far as the primary vote is concerned.

Observers have been reluctant to conclude that these numbers would be sufficient for Labor to maintain its tenuous grip on power, given the likelihood that many Greens voters will have a more apathetic frame of mind next time around.

Galaxy Research has dealt with the issue by averaging preference flows from the last three elections in determining its two-party preferred results, rather than following the usual practice of simply going on the most recent election.

A poll it conducted just last week credited the LNP with a 51-49 lead, despite the two major parties’ primary votes being almost exactly as they were at the election, when the 51-49 result was in favour of Labor.

For both the pollsters and the Labor Party, the situation now becomes a lot more straightforward, with at least three-quarters of Greens voters set to follow their well-established habit of favouring Labor over the conservatives, however reluctantly.

Life may well have become less complicated for the LNP too, though in a less enviable way. Barring a substantial change in political fortunes, the unanticipated trek through the wilderness that began with last year’s shock defeat could now be even longer than it feared.

*For more from William Bowe visit Crikey blog Poll Bludger