Supermarkets have pushed up bread prices by as much as 20p a loaf.
The rise came after bakery giants warned they could no longer absorb the rising cost of wheat, which has surged since 2016’s Brexit vote.
Tesco has hiked prices across its Kingsmill bread range.
An 800g wholemeal and soft white are now £1, up from 80p at the start of last year, while 400g loaves are 15p more expensive at 75p.
Rival Sainsbury’s increased its price of 400g Kingsmill Crusts Away loaves by 5p to £1.30.
Own label supermarket bread is also getting more expensive, with an 800g medium sliced white loaf now 55p on average, up 12 per cent on a year ago.
The UK’s biggest bakers say wheat prices are up 20 per cent – mainly as a result of the declining value of the pound – since the 2016 EU referendum.
The Association of British and Irish Flour Millers said: “Wheat is priced globally so the exchange rate really makes a difference.”
Allied Bakeries, which owns the Kingsmill and Allinson’s brands, has warned the situation is “unsustainable”.
Last November the firm warned commodity inflation – especially for wheat – and lower retail prices had caused a “significant margin decline” in its earnings.
The price hikes come amid wider increases on supermarket bread over the past, says trade magazine the Grocer.
A 400g load of Hovis medium wholemeal is up 13.6 per cent to 78p on average, while a 400g load of Warburtons medium white is 2 per cent more, at 82p.
By last February UK wheat prices were up 38 per cent, at £146 per tonne.
By last month they had fallen back to £139 per tonne, yet they were still well above pre EU referendum levels.