The government has belatedly realised it is in real danger of losing its campaign to convince voters of the merits of its hastily negotiated preferential trade agreement with China, but its inability to explain policy is badly hampering its efforts. And if you look at the polling around what are mistakenly called “free trade agreements”, it becomes clear why the campaign against the China-Australia Free Trade Agreement (CHAFTA) by the CFMEU and now, increasingly, Labor itself, has gained traction.

When CHAFTA was agreed late last year — or more correctly, agreed “in principle” because negotiations were far from finished — voters were supportive of the deal: Essential Report showed voters approving of it 51%-20%. While that wasn’t as good as support for the government’s previous preferential trade agreement with Japan (52%-13%), it should still have augured well for the Coalition, which promoted preferential trade agreements as a critical element of its economic strategy.

Voters generally like “free trade agreements”. They may not understand them (and they certainly don’t understand such deals don’t produce anything more than modest economic benefits, as the Productivity Commission has repeatedly shown), they just tend to support them, probably because the term “free trade” is one we’ve been taught to respond to positively. In fact, the numbers for the Japan agreement were about the same as the numbers for trade agreements generally: 49% of voters think “free trade agreements” of any kind are good for the country, and just 11% don’t.

But buried in the polling is a number that explains what went wrong for the government. While asking about trade agreements, Essential Research asked voters who they thought benefited from them. Over half (52%) said the government itself benefited some, or a lot (presumably politically — in fact trade agreements significantly reduce tariff revenue); 48% said the mining industry benefited (including 22% who said the mining industry benefited “a lot”, easily the highest level on who benefited “a lot”), then Australian business generally (44%), and so on through several other sectors. But just 37% thought the economy in general benefited, and only 25% said working people benefited some or a lot — including just 6% who thought working people would benefit a lot from such agreements”. Over a fifth of voters said workers would receive no benefit from free trade agreements; another quarter said workers would receive little benefit.

Voters think free trade agreements are much better for government and corporations than they are for workers, and it’s exactly the weakness the weakness that the CFMEU targeted right from the outset of its campaign against the agreement. And far from backing down in the face of accusations of racism and links with the CFMEU from the government, Labor has ramped up its campaign against CHAFTA: yesterday Bill Shorten commenced question time with two questions to Abbott about market testing requirements.

That sort of detail is a problem for Abbott — there is genuine doubt that market testing will be required for large-scale infrastructure projects before firms bring in Chinese labour. He wants to stick to the government’s broader narrative is that CHAFTA is a positive for jobs and Shorten is merely a puppet of the CFMEU. But remember the number of voters who think free trade agreements aren’t good for workers: in insisting it will be good for employment, the government is contradicting existing beliefs of voters, while Labor’s message — it will be bad for Australians because jobs will go to Chinese workers — reinforces existing beliefs.

And ask anyone in marketing whether it’s easier to persuade by reinforcing existing views or contradicting them.

As the CFMEU campaign has gained traction and the numbers of voters opposed to the deal has risen, the government has struggled to find a means to counteract it. Part of the problem was Abbott’s rush to announce the agreement last November, partly motivated by his own self-imposed year-end deadline for it: the agreement still needed several months of further negotiations to finalise. But the CFMEU didn’t wait for the text: it began attacking the agreement immediately and had established a fully-fledged campaign, complete with targeted polling, well before the actual text was finally released in June. The government left a vacuum on the issue, and the CFMEU filled it.

When Coalition MPs returned from the winter break In August, they immediately complained that the CFMEU campaign was biting in their electorates, and wanted Trade Minister Andrew Robb to do something; he promptly promised an advertising campaign and the government began strengthening its rhetoric, particularly around accusations of xenophobia. The government also switched tack to arguing that former Labor luminaries Bob Hawke and Bob Carr backed the FTA — a tactic reminiscent of then-Health minister Peter Dutton’s awful attempts to sell the GP co-payment, when seemingly the only argument he could muster in its defence was that Jenny Macklin had been a staffer to Brian Howe in the early 1990s.

Nor has it helped that while the government has been calling the CFMEU racist, it has been playing race politics itself, imposing more red tape on Chinese investment in agriculture and real estate to appease the National Party and give the impression of addressing housing affordability. It is expecting the electorate to process two nearly contradictory messages — Chinese investment bad, Chinese workers good.

Labor remains open to backing the deal if the market testing issue can be addressed, but Abbott may be more interested in trying to damage Shorten by linking him to the CFMEU than in securing an agreement. And Labor’s deployment of the issue in Canning illustrates how potent they believe CHAFTA can be at a time of economic weakness and tepid wages and jobs growth.

Neither side has contributed much to a sensible debate about preferential trade agreements, which are probably a net positive for the economy but mainly from the liberalisation we undertake rather than than what our negotiating partners do. Someone outside the Productivity Commission should be arguing for an Australian Free Trade Agreement, one we negotiate with ourselves to eliminate remaining tariffs and remove impediments to investment, which would yield a lot more benefits than bilateral deals.