Without warning or explanation, Hinch double crossed the government on the backpackers tax and joined forces with rogue One Nation senator Rod Culleton to defeat what was supposed to be a routine vote to set the backpacker tax at 15 per cent.

He had previously voted for the government's original proposition of 19 per cent. When the government couldn't get that through the Senate, he publicly backed the 15 per cent compromise put forward by One Nation, as did the Nick Xenophon Team.

The government thought it had a deal. Now, on the last day of Parliament for the year and one vote short, it is scrambling to get Hinch to change his mind.

Out of nowhere, Hinch proposed overnight a 13 per cent rate. No reason why. No modelling to suggest why it would be better than 15 per cent, no Parliamentary Budget Office Estimate of how much it would cost the budget, no policy proposal to replace the lost revenue.

Understandably, the farmers are filthy. Fruitgrowers with laden trees have not slept for months while this fiasco has played out. On Tuesday, when the government agreed to 15 per cent, they finally had peace of mind. Hinch – and Culleton – shattered that.

Labor and the Greens, who don't care about the issue, other than it being an opportunity to seed chaos in the Coalition, have stuck steadfastly to Jacqui Lambie's proposal of 10.5 per cent and are cheering Hinch from the sidelines.

There is suspicion within government as to whether Treasurer Scott Morrison did the due diligence in locking in Hinch's vote before saying Labor could "go take a flying leap". Not that Labor was ever likely to budge. Farmers don't vote Labor.

The Nationals suspect Hinch adviser John Clements, who worked for Tony Windsor and the Palmer United Party, and doesn't like the Nationals.

The government is angry at Hinch but can't say so because it still hopes to do a deal.

So Turnbull has turned his anger on Labor, wheeling out the rather odd, if unconvincing line, it wants "Rich kids from Germany to pay less tax than a poor kid from Tonga". (Seasonal labourers from the Pacific Islands already pay 15 per cent tax).

Odds are this will be settled by the end of Thursday, but much damage has been done; to the government, to politicians and, most importantly, to primary producers

Whether it is sorted or not, Hinch has defined himself for the remainder of his term. And not in a good way.

It's why people don't like politicians.

This story first appeared on The Australian Financial Review.