Farming subsidies will be paid for looking after the environment in the future, Michael Gove is expected to say as he sets out his vision for a "green Brexit".
he new Environment Secretary is expected to spell out his support for reform of agricultural payments so they support farmers who look after soils, plant trees and protect habitats and landscapes, rather than simply being handed out to landowners.
In his first keynote speech since taking over from fellow Brexiteer Andrea Leadsom, the Environment Secretary will say that leaving the European Union provides a "once-in-a-lifetime opportunity" to reform farming, fisheries and land management.
Speaking at WWF's Living Planet Centre in Woking, Mr Gove will tell an audience of environmental and countryside organisations that Brexit gives scope for Britain to be a global leader in green policy.
Many of the laws on the environment currently come from Brussels, from agricultural policy and farming subsidies to air pollution limits, bathing water quality, wildlife protection and climate action such as energy efficiency standards.
Environmentalists have raised fears over the fate of EU regulation on the environment, amid calls in some quarters to cut "red tape" on everything from energy efficiency to protecting habitats.
They have warned that the process of transferring rules to UK law must not weaken them, but Mr Gove will move to reassure them Brexit will be a force for good.
"Leaving the EU gives us a once-in-a-lifetime opportunity to reform how we manage agriculture and fisheries, how we care for our land, our rivers and our seas, how we recast our ambition for our country's environment, and the planet.
"In short, it means delivering a green Brexit."
Reform of the EU subsidies to support the environment is backed by the Country Land and Business Association (CLA), which represents 30,000 landowners, farmers and rural businesses in England and Wales.
As the UK leaves the European Union, the current EU-wide subsidy regime largely paid on the amount of land farmed should be replaced with "land management contracts" - business contracts to manage land in ways that deliver public benefits, the CLA is urging.
Farmers would receive payments for choosing to deliver services such as storing carbon, managing water quality, connecting up habitats, reducing flood risk or protecting famous beauty spots and important landscapes, the group said.
In his speech, Mr Gove will acknowledge the damage done to the UK and global environment in the past.
"In recent decades we have lost green space, cut down trees, sacrificed meadow and heath land, polluted our earth, air and water, placed species in danger and run down the renewable resources - from fish to soil - on which our future depends.
"And at the same time, across the globe, we've seen climate change threaten both fragile natural habitats and developing human societies, we've allowed extractive and exploitative political systems to lay waste to natural resources and we've placed species of plants and animals in new and mortal danger while gambling with the future health of the whole world."
He will describe himself as an environmentalist because he cares about animals, draws inspiration from nature and finds its beauty important - but also because of "hard calculation" of the need to protect the natural world or face disaster.
And he will say that Brexit will mean taking back control of environmental policy.
"We now have an historic opportunity to review our policies on agriculture, land use, biodiversity, woodlands, marine conservation, fisheries, pesticide licensing, chemical regulation, animal welfare, habitat management, waste, water purity, air quality and so much more.
"Informed by rigorous scientific analysis, we can develop global gold standard policies on pesticides and chemicals, habitat management and biodiversity, animal welfare and biosecurity, soil protection and river management and so many other areas."
He will also say that a "Government of global Britain" should not just lead on security or trade but also champion sustainable development, be a leader in environmental science and an innovator in clean, green growth.
And Mr Gove will add that it should uphold its pledge to hand over the environment to the next generation in a better condition than it is now.
Tanya Steele, chief executive at WWF, said: "The UK has a track record of leadership in addressing global poverty and climate change, and promoting sustainable development.
"We need to address global biodiversity loss as an iconic challenge which demands both boldness and ambition.
"So we're pleased that the Environment Secretary is committed to putting improving the environment at the heart of the Brexit process, and ensuring that this country is an environmental leader on the world stage.
"We look forward to seeing the plans and urgent action that will deliver this ambition."