The EU’s Common Agricultural Policy treats Africa as an economic colony. Brussels applies tariffs to tomato sauce, but not to tomatoes; to chocolate, but not to cocoa beans; to roasted coffee, but not to green coffee. Africa, in other words, is expressly discouraged from developing secondary industries that would add value to its commodities.

How much value? According to Calestous Juma of Harvard Kennedy School, Africa – the entire continent – earned £1.8 billion from coffee exports in 2014. In the same year, Germany alone earned £2.9 billion from coffee re‑exports.

In fairness, the EU has cut its tariffs for some of the poorest countries under an arrangement known as Everything But Arms. African wags, pointing to the many non-tariff barriers that remain, call the deal Everything But Farms. For example, Ugandan researchers may have come up with a GM solution to banana wilt, a disease which costs East African growers half a billion pounds a year. But applying it could lead to the EU blocking all banana imports from the region.

Britain, a net food importer with relatively efficient farms, has never shared the agricultural protectionism of continental states. Once we leave, we’ll be free to buy food at world prices. Instead of giving Africa ineffectual dollops of aid money, we can engage in mutually beneficial exchange. Sure, Africa’s economy is smaller than Europe’s, but this isn’t an either/or choice. We should trade freely with every continent.

Cheaper food would boost our entire economy, freeing up spending power; but the biggest winners would be the poor, who spend the highest proportion of their income on groceries. We’d be promoting social justice at home and development abroad at no cost.