The rapid and sustained slide of the pound is squeezing margins for UK companies that buy goods and services and borrow money abroad at a time when consumers are reluctant to pay more.

The pound has fallen 25 per cent against the US dollar since mid-July, and is now worth $1.50. The drop against the euro has been slower and less sharp, with the pound now worth €1.17, down about 13 per cent since the start of the year.