Advertisement London: In recent days, negotiators have seemed tantalisingly close to striking a post-Brexit trade deal between Britain and the European Union. But time is running out, with less than two weeks until the December 31 deadline when Britain withdraws from the EU's economic zone, the single market and customs union. That could mean heavy new taxes on traded goods, gridlocked ports and some types of food disappearing from British supermarket shelves, as well as conflict over fishing rights. The trading arrangement between the two sides would default to World Trade Organisation rules, and deliver a huge hit to businesses on both sides of the English Channel, but particularly in Britain. Here's why the negotiators talk about a "moment of truth" in the efforts to avoid a chaotic final chapter to the Brexit saga.