Labour has pledged to back farming businesses to boost food security, as more polling suggests the party is edging ahead in the countryside.

A survey found Labour has the support of 36% of rural voters, up from 20% in 2019, while the Conservatives had seen their support fall from 58% at the 2019 election to 32% this year.

The Deltapoll survey released by the National Farmers’ Union (NFU) of 4,000 people including 614 in farming constituencies, also found Sir Keir Starmer’s approval ratings were significantly higher than Rishi Sunak’s in both rural communities and the wider public – though were still in negative territory.

It is the second poll to suggest that Labour is leading the Conservatives in the countryside ahead of the general election.

At the NFU’s annual conference, shadow environment minister Daniel Zeichner promised a Labour government would “resolutely back British farmers”.

“Food security is national security,” he said.

“So, a Labour government will resolutely back British farmers, reducing our reliance on insecure imports, supporting high quality, local produce for consumers, and ending the shameful new reality of those empty supermarket shelves.”

The party would lower the red tape produce faced at borders, seeking a deal with the EU that would get British food exports moving again, and ensure standards are safeguarded, he told delegates.

A Labour government would ensure that at least half of all food in hospitals and prisons is locally produced or certified to higher environmental production standards, he said.

Mr Zeichner said Labour’s plans for a new public energy company would help cut bills for farmers and planning changes would speed up their ability to plug renewable energy into the grid.

There would also be no Scottish-style right to roam for the English countryside, he said.

Mr Zeichner told farmers that Labour was committed to making the environmental land management scheme – which replaces the EU-era subsidies which mostly paid for the amount of land farmed – work, in a way that “ensures the correct balance between food production and nature recovery”.

“Labour’s new deal for farmers is a balanced package that, crucially, recognises that farming is a business, and that if farmers can’t make a return, then our entire food supply crumbles,” he said.

“This is a real deal for farmers that will boost Britain’s food security, protect farming jobs and deliver growth for rural communities.”

His comments come after the Prime Minister paid tribute to British farmers during his appearance at the conference, but suggested farmers were not in the sector for the money, but because they loved it.

NFU president Minette Batters said that for too long politicians had seen farming “as a sort of cottage industry”, warning farms were businesses and “we need to have profitable agriculture”.