Labour has vowed to fight any attempts to water down European Union-imposed environmental laws after Brexit.
Shadow Brexit secretary Sir Keir Starmer will use a speech to demand that all existing EU green laws are put into a new Act of Parliament, claiming it would then be harder for future governments to U-turn on them.
In a speech to Labour environmentalists he will call for stronger protections for EU law than those proposed in the Government's Great Repeal Bill plan.
Sir Keir will say: "A hard Brexit - removed from the single market and outside of common regulations and minimum standards - could be hugely damaging for our environment, our climate and our wider politics and society.
"Labour will fight for a Brexit deal that puts the economy, jobs and living standards first and makes sure there is no watering down of key environmental protections or standards.
"We will call for all existing EU environmental laws to be put into primary legislation through a new Act of Parliament. This would make it far harder for future governments to weaken environmental legislation. And it would enshrine EU minimum standards in UK law."
The Government's plan for a Great Repeal Bill will convert existing EU law into domestic law, "wherever practical", but this may not mean environmental laws being contained in secondary legislation rather than a full Act of Parliament.
Sir Keir will add: "We should make the case for more progressive, more ambitious domestic environmental policy too. Not to match EU standards but to go beyond them."