To be clear, “no deal is better than a bad deal” is a vacuous slogan that should chill your blood. This is a rough breakdown of some of the things that would occur if the UK Government went through with this.
From March 29, 2019, EU law no longer applies to us. The border across Ireland would become an external frontier overnight because there will be no legal way to trade across it. What happens to the Irish peace process is anyone’s guess.
We will not be able to export our goods and services – food, whisky, fish and all the rest – to the EU or anywhere else because we presently do this under EU-negotiated rules. The UK is a member of the World Trade Organisation (WTO) but does not have schedules. Creating these will not happen overnight, and any WTO member can slow this process or even block it for any reason. Once this is sorted out, tariffs will apply in a variety of markets that they don’t currently. Food would not disappear from the supermarket shelves but the impact on the price and availability of food would be significant.
Planes will not be able to enter or leave UK airspace, or even travel through it, because the Open Skies legislation would no longer apply and safety could not be legally guaranteed. EU nationals living in the UK (and UK nationals living in Europe) would face even more uncertainty than now.
The UK banks and financial houses trading across the EU, in the absence of regulation, deposit guarantee legislation or passporting rights, will have to suspend trading in their shares. In all likelihood trading would be suspended anyway due to the massive economic damage going on.
I’m not scaremongering. I have no interest in Project Fear. I’m telling you what would happen if the most extreme no deal scenario were to be played out.  Anyone who pretends the UK can simply walk away is either dangerous or deliberately attempting to mislead you. I hope the no-deal scenario does not arise and I don’t think it will; but let’s be clear, even talking about it is madness.