Every political party is failing to tackle a crisis that has left the UK as “one of the most nature-depleted countries in the world”, the leaders of four major charities have warned.

In a joint op-ed for i, the CEOs of the National Trust, RSPB, The Wildlife Trusts and Woodland Trust, sounded the alarm over the decline of the UK’s natural environment, which they say must play a major role in this year’s general election.

UK species have declined by 19 per cent on average since the 1970s, with one in six species currently at risk of extinction, a landmark report published last year by the Government in collaboration with non-governmental organisations found.

The Government has set a legal target to halt the decline of species by 2030, but nature charities are warning this goal is likely to be missed.

“With an upcoming election, and only six years to meet this legal target, we’re starting to see more political debate on the crisis nature is facing,” the charities said, adding that politicians from all parties “need to be much clearer” on how they plan to turn things around.

“Without action to restore nature to help us adapt to climate change now, future governments will have to grapple with the escalating consequences for all of us, from plummeting food production to property damage from increased flooding,” they warned.

The charities said the public’s love for nature was evident through the outcry over the sewage scandal, which i has covered extensively as part of its Save Britain’s Rivers campaign.

But they said political leaders needed to set out much more concrete plans on how they will improve the state of Britain’s nature before the election.

Harry Bowell, the National Trust’s director of land and nature, told i: “Political debate is noticeably lacking on the crisis nature is facing.”

A spokesperson for the Department for Environment, Food & Rural Affairs said the Government was going “further and faster for nature… with major new schemes for everyone from farmers to housebuilders to help restore nature”. The Government has also launched a £25m Species Survival Fund to support the creation and restoration of wildlife-rich habitats in England.

Labour has said that, if elected, it would uphold the Government’s 2030 target and vowed to create a new land use framework that would ensure 30 per cent of land and sea is protected for nature.

How Britain’s nature is under threat

Every six years the UK reports on the conservation and abundance of the species living within the Great Britain.

The latest version, published last year, found that nearly one in six species were at risk of being lost from Great Britain. On average, species had declined 19 per cent since monitoring began in the 1970s.

Birds were found to be under particular threat with 43 per cent of species at risk of localised extinction in Britain, while 31 per cent of amphibians and reptiles were also at risk.

The hazel dormouse is one species whose population has dwindled in the UK in recent years, down 70 per cent from the year 2000, largely as a result of habitat loss and the management of the UK’s woodlands.

Skylarks, which were in abundance in the UK since the 1970s, have dropped by 56 per cent in line with the intensification of farm management.

Hedgehogs have declined by up to 75 per cent in the British countryside since 2000, while water voles have gone from being a frequent to a rare sight on Britain’s waterways.

Meanwhile, 80 per cent of the UK’s butterflies have declined since the 1970s, with some of the most at-risk types including the Wood White, Swallowtails, Adonis Blues and Large Heath.

Cicadas are one of the most endangered animals living in Britain. The flying insect remains common throughout Europe, but the UK’s population is confined to the New Forest. There have been no sightings of cicadas in the UK for more than 20 years, leading some to believe the species is already extinct. Some of the threats include reduction in habitats and wetter weather owing to climate change.

Britain’s plant biodiversity is also in decline, with 53 per cent of our native plants, such as heather and harebell, decreasing in their distribution.

The Government has previously been criticised for failing to enforce its ambitious environmental targets, with campaigners raising concerns over slashed budgets for the Natural England advisory body and the Environment Agency watchdog.

The charity leaders said the UK needed “better-resourced nature delivery bodies” if our wildlife is to be restored “on a scale not seen before”.

“To be effective, we need these institutions to have the teeth to hold any government of the day to account and have the resources to do their jobs properly.”

The CEOs raised concerns over an upcoming Private Member’s Bill, introduced by the Tory MP Derek Thomas, that could mean the power to designate Sites of Scientific Interest would be transferred from Natural England to the Environment Secretary.

“There is a bigger principle at stake here,” they said. “This change would replace the current expert-led, objective process led by Natural England with one arbitrated by politicians.

“It would rip up science-led decision-making and instead turn our Sites of Special Scientific Interest into Sites of Political Convenience. It would be like stripping powers from the Bank of England to set interest rates independently.”

Time to ‘turbo charge’ nature protection, not weaken it

Hilary McGrady, director-general, National Trust; Beccy Speight, chief executive, RSPB Craig Bennett, chief executive of The Wildlife Trusts and Dr Darren Moorcroft, chief executive of Woodland Trust

From the public outcry over the discharge of sewage into rivers, to the felling of the Sycamore Gap tree, it is clear that the UK public loves nature. Iconic landscapes such as the Lake District or White Cliffs of Dover are hard-wired into our national culture.

Yet the hard truth is that the UK is one of the most nature-depleted countries in the world, with one in six species at risk of extinction.

Without action to restore nature to help us adapt to climate change now, future governments will have to grapple with the escalating consequences for all of us, from plummeting food production to property damage from increased flooding.

This hasn’t passed the public by. Eighty-one per cent of UK adults believe nature is under threat and that more needs to be done urgently to protect and restore it.

The Government has set a strong nature target – the Environment Act requires species decline to be halted by 2030 – but in the words of its watchdog, the Office for Environmental Protection (OEP), its delivery plan has so far “fallen far short” and “opportunities to change course must be taken”.

With an upcoming election, and only six years to meet this legal target, we’re starting to see more political debate on the crisis nature is facing. But politicians, of whatever party, need to be much clearer on how they plan to deliver the course correction the OEP says is needed.

One thing is immediately apparent: we need better-resourced nature delivery bodies to restore wildlife on a scale not seen before.

Natural England and other environmental arm’s length bodies exist for a host of good reasons. Enforcing important protections. Looking after critical assets, such as nature reserves or flood defences. Advising government, based on sound science and evidence. And, in theory at least, making decisions without direct interference from politics and politicians.

To be effective, we need these institutions to have the teeth to hold any government of the day to account and have the resources to do their jobs properly. Yet some in Westminster are pushing in a different direction.

A new Private Members’ Bill proposes transferring the power to designate Sites of Special Scientific Interest, the most protected places for nature, from Natural England to the Environment Secretary. On the face of it, the case may look appealing. Nature enforcement bodies cost money, their local engagement isn’t always as good as it should be, and their track records can always be questioned.

But there is a bigger principle at stake here. This change would replace the current expert-led, objective process led by Natural England with one arbitrated by politicians. It would rip up science-led decision making and instead turn our Sites of Special Scientific Interest (SSSIs) into Sites of Political Convenience. It would be like stripping powers from the Bank of England to set interest rates independently.

SSSIs are our primary nature protection tool. They provide important legal protections for the best of our habitats such as woodlands, moorlands, meadows and freshwater on which all kinds of species rely, and people cherish. They are also fundamental to meeting the commitments made by government to conserve 30 per cent of land and sea for biodiversity by 2030 to reverse nature’s decline. We should be investing in them, to improve their condition and to restore our precious nature urgently to good health, not making them subject to political whim.

Half of all global GDP is underpinned by healthy, natural resources. Attempts to water down the current stringent standards, or to politicise the decisions on where the best protected places for nature, would fail both nature and, ultimately, all of us.