Britain faces a frightening array of economic risks if Parliament makes a mess of Brexit, but a sterling crisis is not one of them.

A weaker exchange rate acts as a shock absorber. It cushions the downturn to some degree and strengthens our buffers against deflation. Those fretting about the inflationary risk of a lower pound are stuck in a timewarp, or living on the wrong planet.

Global bond yields are touching historic lows every day and signalling a deflationary depression into the next decade. This is not like the 1930s. It is worse.

Investors are so frightened - or so short of safe debt to buy - that Switzerland can borrow for 50 years at rates below zero, Germany and Japan for 15 years, and France and Holland for nine years. Roughly $10.7 trillion of sovereign debt and $1 trillion of corporate debt is now trading at negative rates worldwide.

British 10-year yields have collapsed to an all-time low of 0.73pc since the Brexit vote, and 30-year yields are down to 1.58pc. This would not be happening if the bond vigilantes had the slightest concern that Britain was heading into a stagflation trap.

Countries and blocs across the G20 are trying to drive down their currencies - or prevent them rising - hoping to pass the deflationary parcel to somebody else in a beggar-thy-neighbour world.