Britain has gone from being the “sick man of Europe” to one of the continent’s most robust economies in 43 years as a member of the EU and before that the European Economic Community.

When the UK decided by two-to-one to stay in the EEC in 1975, there was an overwhelming economic case for remaining. The country was plagued by double-digit inflation, recession and the three-day week. In the 20 years before Britain became a member the proportion of its trade with the founding six member nations rose from 13 to 21 per cent. In the 20 years after accession British trade more than doubled with them to 44 per cent.

The unanswerable question posed by Brexit campaigners is what level of trade outside the