Jim Tyrrell, boss of Mitsubishi Motors UK, said Britain would be “insane” not to join the euro to help stabilise pricing. “The euro is a political idea and probably not a good one,” he said. “But it exists and it doesn't look like going away.”

The 20% devaluation in the euro since it was launched meant companies were chasing a moving target. “Few businesses can get 20% more efficient in two years so this just leaves them vulnerable to institutionalised cross-border shopping. “The people who gain are the arbitrage merchants – not the businesses who invest for the long term.”