The last time sterling fell off a cliff we were in the midst of global financial crisis from 2007 to 2008. The currency shock sent inflation shooting up to 5.2pc, abruptly squeezing on real living standards.

On that occasion the poor were at least protected. Benefits and in-work tax credits were indexed to inflation. Social cohesion was preserved.

This time the most vulnerable families will take the brunt as the cost of imported food, clothes, and fuel suddenly jump. A parting gift of the last Government was to freeze benefits for 11.5 million households until 2020.

This is a political time bomb that will detonate next year when the inflation ‘pass-through’ from imports bites in earnest. It threatens to poison the already fractious national debate unless steps are taken to mitigate the damage.