The National Farmers’ Union (NFU) raised questions about the government’s proposed targets on water pollution, tree planting and rewilding, calling them “irrational” and “unachievable”, according to documents published by the environment department.

Under the 2021 Environment Act, the government was required to set legally binding targets for nature recovery and environmental improvements. It began consultation on those targets in March 2022, recommending, for example, an increase in tree canopy and woodland cover from 14.5% to 17.5% of total land area in England by 2050. Water pollution reduction targets were initially set for 2037.

After the consultation closed and the targets were published, there was some disappointment. The tree canopy target had been reduced to 16.5%, while the water pollution target had been delayed to 2038.

The newly published consultation documents show that the NFU’s response was highly critical of the initial proposals.

The lobby group, which represents powerful voices in the agriculture sector, said proposals to reduce nutrient pollution from animal waste and fertiliser were “irrational”.

It told the government: “Broadly, we consider the level of ambition across the nutrient targets to be unachievable, inconsistent and irrational. The NFU and its members are committed to building on past successes and further reducing nutrient losses to the environment from agriculture. However, this effort must be balanced with the need to produce food, fibre and energy on farm, thereby protecting the rural economy and maintaining food security.”

The union also said it did not agree with targets to reverse species extinction, and in particular spoke out against reintroducing lost species. It said: “The NFU has long advocated that we should support species that are already present before we seek to introduce new species. So instead, we believe that we should aim to prevent the loss of species, as such a bespoke target approach to rare and threatened species could be beneficial in driving action to reduce biodiversity loss.”

It argued that the concept of rewilding was damaging to the countryside, warning against “adopting an approach that risks undermining the social fabric of rural communities”. It said: “Rewilding, for example, ignores the fact that our iconic farmed landscapes are valued by the many who make 4bn visits to the British countryside each year.”

It also said the tree planting target of 17.5% coverage was too ambitious. “An increase in tree canopy and woodland cover from 14.5% to 17.5% equates to 415,000 hectares of tree cover by 2050, approximately 15,000 hectares of trees a year. This is extremely ambitious, if not unachievable,” it said.

Nature groups said the union was “deluded and dangerous” and that it was “stunting progress towards a greener future” after its lobbying against nature restoration policies was revealed.

Rob Percival, the head of food policy at the Soil Association, said: “The NFU’s attitude towards environmental targets is defeatist, deluded and dangerous. There is clear scientific rationale for regenerating woodlands and increasing tree cover, but the NFU thinks it’s too difficult. Our rivers are choking on excess nutrients, primarily due to the proliferation of intensive livestock systems, but the NFU has dismissed pollution reduction targets as ‘irrational’. Instead they propose more of the same – more poultry, more pollution.

“It’s bizarre and unfortunate that the NFU is displaying such a lack of imagination when the stakes are so high. Resolving the climate and nature crises will entail difficult trade-offs in land use, and a radical shift in the way that we eat and farm. With the right policies in place, farmers and producers can be paid to lead the change. In adopting such an obstructionist stance, the NFU is letting down its members, failing the public, and stunting progress towards a greener future.”

A Defra spokesperson said: “We have full confidence in our Environment Act targets, which were established through intensive consultation with businesses, land managers and environmental organisations. The delivery of these targets will require a shared endeavour across the whole of government, business and the individual decisions we all make, and through the Environment Act we have ensured a robust legal framework to hold current and future governments to account, protecting nature for generations to come.”

NFU director of policy Dr Andrew Clark said: “British farmers share the government’s environmental ambitions, but these targets must work in tandem with producing quality, sustainable food.

“The government’s own land use strategy seems to conflict with its ambitions for nature as well as delivering on its self-sufficiency targets, as set out in the national food strategy.

“Our consultation response highlighted that we need environmental targets which are ambitious but deliverable, and which sit alongside equally ambitious plans for domestic food production and UK food security.”