It was the puddles of green sludge left by the tires of massive tractors in western Belgium’s industrial farmlands that drew the attention of biological engineer Ineke Maes.

The slime was destructive algae, the result of the excess of chemicals used by farmers to boost their crops, but at a high cost to nature. Maes had hoped the European Union’s environmental policies would start to make a fundamental difference by improving exhausted soils.

In recent weeks, some of those tractors moved off the land and onto the roads, blocking major cities and economic lifelines from Warsaw to Madrid and from Athens to Brussels. Farmers were demanding the reversal of some of the most progressive measures in the world to counter climate change and protect biodiversity, arguing that the rules were harming their livelihoods and strangling them with red tape.

And the impact has been stunning.

The farmers' protests affected the daily lives of people across the 27-nation bloc, costing businesses tens of millions of euros in transportation delays. The disruption triggered knee jerk reactions from politicians at national and EU level: they committed to rolling back policies, some of them years in the making, on everything from the use of pesticides to limiting the amount of manure that could be spread on fields.

To environmentalists like Maes, who works for the Belgian Better Environment Federation umbrella group, it would almost be laughable if it were not so depressing.

Read: Farmers from 10 EU countries protest agricultural policies

“In the environmental movement, we joke that we should get tractors ourselves to make a point. Then we would be competing fair and square. The purpose should be that we get negotiations, and that we get a deal through democratic process — the rules, you know," she said. Reasoned arguments, she says, have been drowned out by the rumble of tractor engines.

And there's no end in sight.

After hundreds of tractors disrupted the EU summit in Brussels early this month at a volume that kept some leaders awake at night, farmers plan to return on Monday. They intend to be there when agriculture ministers discuss an emergency item on the agenda — the simplification of agricultural rules and a decrease in checks at farms that environmentalists fear could amount to a further weakening of standards.

The political noise level from the tractors — not to mention the loads of manure dumped outside official buildings — does get through, officials said. “That puts a bit more pressure on the ministers inside. So I would believe that ministers will be a bit more — insisting to have concrete results,” said a high-level EU official, who asked not to be identified because the meeting has yet to take place.

It is this attitude that drives the environmental lobby and NGOs to distraction: knowing that scientific arguments are too often no match for the rule of the street. As a result, the EU's flagship Green Deal, that aims to make the continent carbon-neutral by 2050, is under threat.

“You really should not lose that long-term view, that vision of the future when you are working on policy,” said Maes. “You should not respond to the issues of the day by simply scrapping very important rules that have been seriously discussed, considered, that have been included in environmental impact reports and so on — and that have also been democratically approved in that way.”

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Yet ahead of Monday's farm protest and meeting of agriculture ministers, EU Commission President Ursula von der Leyen, for many the most powerful EU politician, insisted that she “remains fully committed to delivering solutions to ease the pressure currently felt by our hard-working farming women and men.”

Von der Leyen's change in emphasis comes ahead of the June 6-9 elections, when a good showing by her Christian Democrat group, the European People's Party, will be key to keeping her at the helm of the all-powerful Commission. As her party has swayed toward putting farmers and industry first, so has she.

“It is a bit difficult putting a pin on Mrs. von der Leyen,” said Jutta Paulus, a Green member of the European Parliament. "She started off in 2019 being a climate and environment champion, more or less saying, ‘We don’t need the Greens anymore, we are green ourselves.’ And now she says: ‘Well industry called me and they are worried. So I have to do something.’”

In the wake of the tractor protests, action came fast and furious.

Early this month, von der Leyen's Commission shelved an important anti-pesticide proposal, insisting “a different approach is needed.” She also allowed farmers to continue using some land they had been required to keep fallow to promote biodiversity. And the proposals on the table for Monday's meeting about simplifying paperwork go in the same direction.

At the same time, a nature restoration law which was seen as another element in the Green Deal aspiration has already been watered down to appease farmers before it goes to a final legislative vote next Tuesday.

And at a national level, politicians have been bending the same way, from France to Spain and Belgium.

Read more: Protesting Indian farmers clash with police for a second day as they march toward the capital

Flanders, in northern Belgium, has already relaxed its policy on the use of manure which was intended to limit emissions of nitrates that can harm water quality. Under pressure from multinational food manufacturers, whose processing plants dwarf even the biggest family farms in western Belgium, farmers are likely to stick with the industrial methods that exhaust soils and pollute waterways, Maes fears.

“It is mind-boggling that this whole process is now grinding to a halt,” she said.