What is the difference between the customs union and single market and what do they mean for Brexit?

These two core EU systems are often confused, but as Joe Watts explains, how closely the UK stays connected to either or both will affect the way the country operates in the future

Caught between a rock and hard place? (Getty)

The customs union and single market are two fundamental elements of the EU, and are at the heart of the Brexit debate.

But even at this late stage in the Brexit process there is confusion about them, between them and on how the different factions in parliament feel about them.

Put simply, the customs union forms a single territory for customs purposes – no tariffs are paid on goods moving about within the EU, while all EU members apply the same tariffs to goods coming in from outside the bloc.