The prime minister has promised to launch his food security index to farmers, as extreme bouts of wet weather this spring have raised issues around British food security.

M&S Hedge End fruit veg

British fruit and veg farmers have been hit by flooding, high energy prices and trade deals

At a farm to form summit held at Downing Street yesterday, Sunak said: “I know for many farmers the impact of adverse weather in recent months has made working the land even harder, but my message is clear, our support for you is unwavering and we will be with you every step of the way.”

The index will measure how much of the food consumed in the UK is produced domestically, based on government data.

Sunak also announced a replacement for the EU horticulture resilience scheme, aiming to double to £80m a year the amount of funding given to fruit and vegetable producers – a sector that has been badly hit by falling staffing levels since Brexit.

The announcement comes as farming confidence hit its lowest levels since records began, with a survey by the National Farmers’ Union showing 82% of respondents say their farm business has suffered fairly negative or very negative impacts from recent flooding.

The survey found that farmers feel that profitability has also fallen, with 65% saying profits are declining and that their businesses might not survive.

Waning farmer confidence, combined with decreasing food security, means that the UK could become dependent on foreign imports for a third of its wheat.

The president of the Country Land and Business Association (CLA), Victoria Vyvyan, said: “The public expect greater self-sufficiency in fruit and vegetables and farmers can provide it, but the government must ensure its plan is ambitious and workable.

“We call on the government to go a step further by developing a robust and bold plan for the rural economy as a whole. The rural economy is 19% less productive than the national average, but closing that gap would add £43bn to national GVA [gross value added].”

Steve Reed, shadow environment secretary, said: “After 14 years of Tory failure, our farmers are at breaking point.

“The Conservative government has stood idly by as farmers – including our great fruit and veg growers – have been devastated by flooding, skyrocketing energy prices and undermined by dodgy Tory trade deals. As a result, thousands are being forced out of business.”

The environment secretary, Steve Barclay, said: “This announcement will turbocharge the growth of our horticultural sector, supporting the building of cutting-edge glasshouses and innovative farming techniques to put British fruit and vegetables on our plates all year round.”