The outcome of the EU referendum will have profound implications for the future of our countryside, wildlife, rivers and seas. WWF is not telling people how to vote, and we know that voters will be weighing up a range of issues when casting their votes on 23 June. But our supporters, staff and volunteers all share a concern for nature - and David Cameron's intervention should move the environment up the agenda in the referendum debate.
The evidence shows that the EU, and the UK's membership of it, has on balance had a positive impact on the environment in the UK, across Europe and indeed globally, ranging from protecting forests and wildlife and preserving rare species to improving air and water quality, and cutting global emissions.
EU standards have safeguarded streams and rivers that are home to much-loved British wildlife such as water voles, kingfishers, brown trout, otters and the bittern. They have helped protect and restore precious heaths and woodlands that are essential for butterflies and bees.
The UK is no longer the dirty man of Europe; over 95% of our beaches meet tough EU standards for cleanliness. When UK goverments have fallen behind, the EU has been able to hold them to account and demand improvements. That's why our beaches are cleaner.
Recycling is up 400% since 2000, largely thanks to EU legislation which the UK government helped shape. And we would like the UK to continue playing a leading part in Europe's environmental future. For example, it led the way in negotiating reductions in CO2 emissions to help fight climate change, most recently helping to secure an ambitious global climate deal in Paris.
There are things that the EU got wrong - most notably in its Common Agriculture Policy, which was designed to boost food production across Europe. This has resulted in increased damage to our natural environment across the EU, and WWF wants to see it reformed.
We all want the best for the UK's natural heritage. But nature doesn't observe national boundaries. And with environmental challenges growing, this would be the worst possible time to reduce our commitment to protecting nature.