Britain’s national parks need to be much wilder to tackle the nature and climate crises, campaign group Rewilding Britain has urged.

It has launched a new campaign calling on the Government and devolved administrations to create core rewilding areas – where natural processes are restored across the landscape – on public land over 10% of the national parks.

The charity is also calling for legislation on national parks to be modernised to help them increase their efforts to boost nature and curb climate emissions.

The UK has been described as one of the most nature-depleted countries in the world, and the Government has committed to protect 30% of the nation’s land by 2030 to support the recovery of wildlife.

But conservationists warn much of the existing protected areas are national parks and Areas of Outstanding Natural Beauty (AONBs) which do not necessarily deliver for nature.

In England’s national parks, many Sites of Special Scientific Interest (SSSIs), designated for their natural qualities, are in poor condition, and average woodland cover in some parks is lower than some major cities.

The independent Glover Review into England’s national parks, which reported to the Government in 2019, recommended setting up wilder areas – but ministers have yet to respond to the findings.

Guy Shrubsole, Rewilding Britain’s policy and campaigns coordinator, said wilder national parks could lead the way for a healthier, more nature-rich Britain, and provide opportunities for local communities and economy.

Rewilding 10% of the parks would restore peatlands, moorlands, woods, rivers and coasts with no loss of productive farmland, Rewilding Britain said.

Another 50% should be “nature recovery areas” with a mix of habitats, wildlife corridors and land uses and Government financial support for nature-friendly agriculture, the organisation urged.

Land ownership mapping carried out by Rewilding Britain suggests that the Government can create rewilding areas across 10% of the national parks, regardless of action by private landowners.

Public bodies, including water firms which are legally obliged to help the parks meet their purpose, own 738,000 acres or 13% of the area covered by Britain’s 15 national parks, the organisation said.

There is a need to update to legislation dating back as far as 1949 as current laws mean the parks as planning authorities can restrict built development but have few powers to protect and restore nature, Rewilding Britain said.

Mr Shrubsole said: “Nature would be in an even worse state were it not for the parks, but we’re being outpaced by the nature and climate crises.

“Despite some superb initiatives, the parks’ ability to upscale nature’s recovery and lead the way is being hobbled by decades-old laws dating as far back as the 1940s.

“It’s time for change. Without wilder national parks, the Prime Minister’s pledge to protect 30% of Britain for nature by 2030 is just not credible.”

Rewilding involves large scale restoration of ecosystems, with woodland and pastures allowed to regrow, rivers and wetlands returning to a more natural state, and native livestock – or even beavers – used to manage the landscape more naturally and support other wildlife to return.

It has proved controversial in some quarters amid concerns it involves abandoning land that should be used for food production.

But supporters say it can boost jobs in areas such as conservation and eco-tourism, while helping nature and allowing food production to continue.