A morning coffee could become a luxury item rather than an everyday essential, an Edinburgh roaster has warned, as inflation returns to a four-decade high.

A flat white could soon set you back more than £4 with the soaring price of milk, which has seen it reach the highest ever recorded, forcing businesses to bump up prices.

Robi Lambie, coffee roaster and co-founder of Cairngorm Coffee in the Scottish capital, said he was “very concerned” about the impact of inflation on the business.

With everything considered, we predict the price of a flat white coffee will be at least £4 by the end of the year.

“One worry we have is that rising costs could push the price of coffee into a bracket where customers decide it’s more of a luxury lifestyle decision, rather than everyday morning essential,” he said.

“With everything considered, we predict the price of a flat white coffee will be at least £4 by the end of the year.

“It sounds ludicrous, but it’s the position we’re likely to find ourselves in.”

The warning came as the Office for National Statistics (ONS) said on Wednesday that Consumer Prices Index inflation reached 10.1% in September, compared with 9.9% in August.

It was above the expectations of economists, who had predicted the slightly lower figure of 10%.

Darren Morgan, the ONS director of economic statistics, said the rise was in part driven by further increases across food, which saw its largest annual rise in more than 40 years.

These went up by 14.5% compared with the same month last year, representing the largest annual rise since 1980, according to data modelling

As the cost of food rises, so does the cost of milk. The average price of a pint of milk in August was 62p, the ONS said, which is the highest since records began in 1971.

Mr Lambie said that milk had been “significantly undervalued” for some time so it brought the price to a “more realistic price point”.

But he warned: “That does, however, mean margins are tightened and the cost passed on to the customer becomes higher.”