Leaving the EU would encourage politicians to tear up decades of environmental protections, some of the UK's most eminent naturalists have warned.
In a letter to environment secretary Liz Truss, the academics and conservation experts say that, far from being "red tape", the rules and regulations coming out of Brussels have been "critical" to improving the quality of Britain's water, air and natural environment.
Here are six ways the EU has improved Britain's environment over the decades:
1. Clean beaches
EU regulations on water quality have helped in cleaning up Britain's beaches. Nearly 600 coastal bathing areas are monitored for potentially dangerous bacteria - with minimum standards set out for safe bathing - which have to be displayed. This pressure has resulted in the significant increase in water quality.
2. Fish Stocks
EU wide fishing restrictions have had a dramatic effect in preventing overfishing. Last year cod and haddock showed a dramatic recovery.
3. Air quality
Steep reductions in sulphur and nitrogen oxide emissions helped ensure that the most serious urban smog and acid rain episodes no longer occur at the rate and intensities we have seen in the past.
4. Energy Consumption
The EU ban on incandescent lightbulbs now saves average UK households £83 a year, while the eco-design directive has lowered energy consumption in many white goods.
5. Species protection
The EU's Birds Directive has significantly contributed to the protection of species most at risk of extinction. There is clear evidence that most threatened species are progressing better as EU conservation efforts prove more successful than those carried out on a national level.
6. Climate Change
The UK was instrumental in persuading the EU to adopt "at least 40 per cent" carbon reduction commitment for 2030 against opposition from some Eastern European states that rely heavily on coal.