Conservative MPs have urged the Government not to cut the budget for nature-friendly farming, saying it would harm food security and threaten farmers’ livelihoods.

The Chancellor is reportedly considering a £100m cut to funding for nature-friendly farming as she seeks to save billions at this month’s Budget while avoiding a return to austerity.

The figure is said to represent an underspend on the £2.4bn budget for the environmental land management scheme (Elms), with civil servants struggling to justify the extra money to the Treasury.

But Conservative MPs, including shadow net zero secretary Claire Coutinho, insisted in a letter to the Chancellor that such an explanation “will not wash”.

They said the previous government had “intentionally left room in the budget to make sure that it could accommodate the maximum possible uptake of the Elm schemes”.

The MPs added: “The whole budget should be spent for its clear purpose: to support farmers, food security, and nature recovery. At a time of significant financial and environmental pressures, cutting this budget would be a short-sighted act of self-harm.”

Elms replaced the European Common Agricultural Policy after Britain left the EU, and were designed to pay farmers to support nature, rather than simply paying them according to the amount of acreage they farmed.

In opposition, Labour said the underspend of the Elms budget showed the Conservatives had “broken yet another promise to our farmers” and promised to “cut through the Tory bureaucracy” preventing the money from being distributed.

On Monday, Conservative MPs told the Chancellor cutting the Elms budget would “threatens the livelihoods of farmers, who are struggling like never before with high costs and the impacts of extreme weather events, and would harm our food security too”.

“It will also cast into serious doubt the government’s ability to hit the 2030 nature recovery target, which your party has consistently said it supports, with an estimated 239,000 hectares less of farmland under Elms if the budget is cut.”

Other signatories to the letter include former ministers Esther McVey and Helen Whatley and Commons Culture, Media and Sport Committee chair Dame Caroline Dinenage.

The message has also been endorsed by former environment minister Lord Goldsmith and former cabinet minister Lord Grayling.

Nature groups have also opposed any cuts to the Elms budget, saying the money for nature-friendly farming needs to be increased.

A Government source said: “The Conservatives left Britain facing the worst economic inheritance since the Second World War because they refused to make the tough decisions and spent money that didn’t exist.

“The Chancellor has been clear that difficult decisions lie ahead to repair the colossal damage left by the Conservatives and address the £22 billion hole in the public finances.

“Decisions on how to do that will be taken at the Budget in the round.”