The UK faces its worst cereal and oilseed harvests in decades as heatwaves and droughts cut yields, an energy and climate non-profit has warned.

Drawing on provisional estimates from the Agriculture and Horticulture Development Board (AHDB), the Energy and Climate Intelligence Unit (ECIU) said the country's cereals and oilseeds harvest could fall to 19.5 million tonnes if current yield assumptions hold.

It would make 2026 the "worst harvest on record since detailed records began in 1984", the London-based group added in a statement.

ECIU said that would leave production around 2.5 million tonnes below forecasts issued earlier this year by the US Department of Agriculture and European cereals association Coceral.

Lower production is estimated to cost UK arable farmers between £293m ($394.5m) and £390m in lost revenue at current prices.

AHDB's estimates suggest wheat, spring barley and oat yields will all decline, with wheat seen at 6.8 tonnes per hectare, below the ten-year average.

More than half of the wheat crop has already been harvested.

Tom Lancaster, ECIU land, food and farming analyst, said: "At the start of spring, farmers were hopeful of a better year, but the dry April and July and record-breaking heat have left farmers facing down the barrel of a third awful harvest in a row."

He added: "Farming is now the sector most exposed to climate change and the risks and damage that it brings."

The poor outlook follows extreme weather across key growing regions.

Provisional Met Office data shared by the ECIU shows England and Wales recorded their driest July on record, while Southern England saw its driest month ever in a series dating back to 1836.

England received 6.5mm of rain in July, or 10% of its long-term average, while Wales recorded 9.3mm, or 9% of its average.

Martin Lines, Nature Friendly Farming Network CEO and a farmer in Cambridgeshire, said in the ECIU statement: "[The] harvest this year has been a real kick in the teeth.

"Even farmers I know who were sceptical of climate change are now saying they're really worried about the future of their businesses and production."

"UK on brink of decades-low cereal crop – research" was originally created and published by Just Food, a GlobalData owned brand.