Barnaby Joyce is an economic illiterate with a deeply troubling paranoia about Chinese investment. His primary contribution to public debate while he was shadow finance minister was to claim that Australia could default on its sovereign debt. His primary contribution as spokesman on water, after his sacking from the finance portfolio, has been to aggressively champion the interests of Cubbie Station, down the road from his home town.

Joyce, and his Nationals colleagues, not merely want to block the sale to Chinese investors of a property that only exists because of Queensland’s astonishingly lax water regulation in the 1990s, but to waste taxpayers’ money bailing it out.

It is bad enough that we have a party in power that feels the compulsion to bail out industries like the car industry when their foreign owners suggest they might withdraw. But to demand bailouts when investors want to enter a business, purely because of their nationality or their race, is quite something else.

Joe Hockey has commendably fought the good fight internally on this issue, although he appeared to suggest yesterday that Joyce, who in addition to being a shadow cabinet member, is Nationals Senate Leader, and party leader Warren Truss “don’t speak for the Nationals” — a statement that is a political peculiarity and plain wrong: sadly, this sort of xenophobic rubbish is all too typical of the Nationals. Hockey took the opportunity to talk more widely about the growing protectionist sentiment abroad in public debate, bagging local preference in government procurement.

It is correct and brave stuff from Hockey. Voters harbour deep-seated protectionist views, although as Hockey noted, they conveniently forget them when they fill the supermarket trolley. But there’s never much love for politicians prepared to speak bluntly about that hypocrisy.

Also speaking sense was Bill Heffernan, who’s probably forgotten more about water issues than Joyce will ever manage to learn. Heffernan pointed out to David Crowe at The Australian that the key, overlooked issue on foreign investment was transfer pricing and the impact on tax revenue. That’s an issue the Greens, who also have a reflexive problem with foreign investment, might do well to pursue.

One of the reliable double standards of economic debate is also playing out here. Labor is routinely accused, not merely by the Coalition (Hockey repeated the line on the ABC last night) but the commentariat, of creating “sovereign risk”, which used to have a highly specific definition but which, in the hands of business leaders and conservative commentators, these days apparently means any government policy they don’t like.

Yet here is a senior Coalition frontbencher, a man with pretensions to become the deputy prime minister after the next election, calling foreign investment “a bloody disgrace” and demanding the government intervene to overturn a commercial transaction. That’s a damn sight more sovereign risk than a mining tax or a carbon price. Yet not a word from the usual suspects.

Joyce has no place being anywhere near economic policymaking. His views were out of date in the 1970s, when he was being educated at one of Sydney’s top private schools. He is a shadow cabinet member who has directly contradicted Coalition policy and he shows no sign of ceasing to give voice to his dissent. He and the xenophobic elements of the Nationals that he represents undermine the economic credentials of the alternative government and are a direct threat to the foreign investment that is so important to the Australian economy.

Tony Abbott again should dump him, this time onto the backbench. There he can talk all he likes about his obsessions.