Brexit has already cost the equivalent of an average weekly wage for every worker in Britain.

Scottish, Welsh, and Northern Irish families have taken the biggest hits to their living standards, according to the most detailed analysis yet of the inflation which followed last year's Leave victory.

Economists have calculated that price rises provoked by the crash in the pound means the average UK household is losing £400 a year. Residents in the Celtic nations are suffering most because imported foodstuffs and other products make up a bigger share of their spending.

Loading article content

Londoners are losing out least because rent and mortgage payments - which do not depend on the exchange rate - account for more of their expenditure.

Thomas Sampson of the London School of Economics, one of the report's authors, said: "Even before Brexit occurs, the increase in inflation caused by the Leave vote has already hurt UK households.

“Our results provide compelling evidence that, so far, UK households are paying an economic price for voting to leave the EU.”

Sterling plunged to a 31-year-low on the morning of the narrow Brexit vote last year. Prices for many imported goods - such as consumer electronics and, especially, food - have gone up as a result.

Dr Sampson - and colleagues at the LSE's Centre for Economic Performance - do not claim all UK inflation was caused by the Brexit vote.

UK inflation has jumped from 0.4 per cent to in June 2016 three per cent in September 2017. But other advanced economies, such as the United States and EU, have also seen price rises, just not quite so steeply.

Experts have calculated the Brexit effect as 1.7 percentage points of inflation or depressed wage growth from the vote in June 2016 to June 2017.

They report said: "UK inflation increased by 1.1 percentage points more than euro area inflation.

"Our estimates suggest that this naïve comparison probably understates the magnitude of the referendum effect.

"The baseline estimate implies that by June 2017, the Brexit vote was costing the average household £7.74 per week through higher prices "This is equivalent to £404 per year.

"Even acknowledging the uncertainty attached to this estimate, it is clear that the inflationary effects of the Brexit vote have already imposed a substantial cost on UK households."

The analysis does not include the additional cost of holidays or foreign travel after the pound's crash.

Experts said the biggest inflationary effects were for products with a high import content. This can include bread and cereals; milk, cheese and eggs; coffee, tea and cocoa; beer; wine; furniture and furnishings; and jewellery, clocks and watches.

Even service industries like hotels and restaurants have suffered a Brexit inflation effect, albeit a small one, because some of their inputs, such as food, are imported.

The analysis, however, stressed that the exchange rate collapse - the pound lost around 10 per cent when the result was announced - was not the only potential cause of inflation. Investment decisions, it said, could have changed in response to the vote, with a potential price consequence.

Dr Dennis Novy of The UK in a Changing Europe, which funded the research, said: “Our research is not a Brexit forecast. It is about the costs of Brexit that have already materialised. The results show that living standards in the UK have already suffered.

“Households all across the country are hit by higher inflation – without matching pay rises. The increase in inflation can be directly traced back to last year's referendum when the sterling exchange rate dropped sharply.

Britain's economic outlook, meanwhile, looks much grimmer than that of the rest of the EU.

The International Monetary Fund last week upped its prediction of EU economic growth to 2.4 per cent this year. It downgraded its forecast for the UK to 1.7 per cent. The body also expected the EU to outperform the UK in 2018.

However, the IMF, in its regular report on the EU economy added a warning on the prospect of a no-deal Brexit.

It said: "If the UK leaves the EU without an agreement, there will be a notable increase in trade barriers, potentially accompanied by disruption of services in various sectors, with significant negative impact on economic activity."