The Tories need to get it into their heads that marmalade and crisps won't save post-Brexit Britain

Twice this month, Prime Minister Theresa May's government has suggested that the key to Britain's economic future is to increase production of jam and marmalade.

Her Department for International Trade was mocked for an October 3 tweet that said "France needs high quality, innovative British jams & marmalades." (It was even funnier because the second-best selling jam brand in Britain is Bonne Maman, from France.)

Then, on October 18, Department for Environment, Food & Rural Affairs Minister Andrea Leadsom launched a trade initiative that proposed "An extra £185 million in exports to Japan through demand for classic British products like tea, jam and biscuits and new opportunities for British beef."

The implication is that Britain's post-Brexit economic future will be based on accessories for toast.

This is probably more about appearances than substance. But there has been a string of unforced errors from the Conservatives that suggest the official party of business doesn't know much about business.

Back in January this year, Conservative MP Zac Goldsmith appeared at a tech startup event at FabLab to promote his doomed bid to become the mayor of London. He was asked what his favourite tech startup was. He couldn't name one: "Tech startup? I don't know," he said. "FabLab, does that qualify? Probably not." Indeed, not. FabLab is a workspace venue for other tech startups. It was literally the room he was standing in, not a tech startup in the usual sense.

Then, on October 3, Chancellor of the Exchequer Philip Hammond gave a speech to the Conservative party in which he admitted he knew little about the UK tech sector. "Driverless cars, Graphene, the Internet of Things, artificial intelligence, 3D printing, virtual reality, advanced robotics. I'll be honest with you: I had no idea until a few weeks ago just how much I don't know! And even less idea how much I wouldn't be able to understand even once it had been explained to me!"

After that came Home Secretary Amber Rudd's proposal to require companies to list the number of foreign workers they employ. She promoted the idea in an interview with Radio 4 by trashing one of Britain's best furniture companies, Collins and Hayes, which occasionally employs Romanian workers when demand hits a peak. The company is based in Rudd's own constituency, where it provides 98 jobs local jobs, 75% of which are held by British natives. (CEOs hate the proposal because of all the meaningless red tape it will require.)

And then there was Liam Fox, the new Secretary of State for International Trade, who on September 13 said that Britain has "become too lazy, and too fat" and its executives take Friday afternoons off to play golf:

"When I look at how this country was built on free trade, as an outward-looking trading nation, and I look today at the proportion of British businesses that export beyond our borders, and what is it - 80%, 60%? 11% of British businesses now export. ... Companies who could be contributing to our national prosperity, but choose not to, because it might be too difficult, or too time consuming, that might not be able to play golf on a Friday afternoon."

It won't all be jam and no golf after Britain leaves the EU, of course.

There will be crisps, too.

The pro-Leave Brexit Central news site gave a headline to Tyrrells last week, which celebrated the fact that its new American owners intend to invest more in the company because they believe that crisps are immune to recessions. "In 2008, during the last recession, none of the premium crisp brands suffered and I don't think they will this time either - if there is a downturn," managing director Mike Hedges told the Press Association.

Theresa May herself has generated a couple of headlines suggesting she is less than interested in how businesses do things in the real world. She disbanded David Cameron's business advisory group, which previously met the former prime minister quarterly to give updates and strategic advice on what was happening in the world of private sector jobs and investment. May will not be short of advice from business, of course. But it looked bad.

The problem here is that no serious person in economics or business believes that Brexit will actually be good for the economy. The EU Single Market is by far the biggest British trade partner. More than 38% of our exports go to EU countries. And now we are losing our access to the Single Market, or at least only getting it on disadvantageous terms.

Both Japan and the United States have made it clear that their businesses in the UK need unfettered access to the Single Market. If they don't get it, "these costs are likely to be borne by British workers and consumers," the Americans said.

So May is facing tough odds in her fight to convince everyone that somehow, despite the weak pound and a tariff barrier on Europe, Britain will somehow get stronger. Nissan is implicitly threatening to abandon its Sunderland car manufacturing plant, costing us thousands of jobs. And in response, the Tories are trying to sell jam to the one country that sends us more jam than anyone else. (And oh, by the way, that country will be well within its rights to set an import tax on our jam in 2019.)

That's why all this stuff about marmalade and biscuits looks so feeble. No doubt May has a plan to fix it.

This is an editorial. The opinions and conclusions expressed above are those of the author.