Dutch farmers have dealt a blow to Prime Minister Mark Rutte's environmental plans, ploughing up the political landscape to win elections that will shape the upper house of parliament.
Exit polls show the Farmer-Citizen Movement (BoerBurgerBeweging, BBB), which was founded less than four years ago, riding a wave of recent protests to win the most seats in the Dutch senate.
The farmers' party immediately vowed to challenge the government's plans to cut nitrogen emissions by reducing livestock numbers and possibly closing some farms.
"What is happening here? We really knew we were going to win, but this is so indescribable," stunned BBB leader Caroline van der Plas told public broadcaster NOS.
She described the nitrogen plans as a "kind of dogma dictated from The Hague".
The BBB is on course to win 15 seats in the 75-seat senate, ahead of the 10 seats of Rutte's centre-right party, based on exit polls from provincial elections that also determine the make-up of the upper house.
The farmers could now work with other parties in the senate to block nitrogen legislation proposed by Mr Rutte's four-party coalition, which is on course to lose eight seats to put its total at 24.
The Netherlands has been rocked by months of rowdy demonstrations in which farmers blockaded government buildings with tractors, winning support from international figures including former US president Donald Trump.
Thousands of farmers rallied in The Hague on Saturday. They also used tractors to blockade the location of a televised party leaders' debate on the eve of the election.
But their cause has struck a chord in the Netherlands, a country with a proud farming tradition that despite its small population of 18 million is the world's second largest agricultural exporter after the United States.
The Dutch government says it needs to reduce nitrogen emissions by 50% by 2030, blaming fertilisers and manure from agriculture in particular for pollution.
It says it must comply with a Dutch court order saying it had breached European Union rules on nitrogen emissions affecting soil and water.
But the farmers say they are being unfairly targeted by the still unfinalised proposals compared to sectors such as construction, industry and transport.
"We don't really feel heard," Erik Stegink, national president of the BBB and a pig farmer himself, said ahead of the vote.
"Sometimes we don't even feel welcome in our own country anymore."
BBB secures 31.3% of vote in its heartland
Exit polls show the farmers' party in first place in all the provinces surveyed, including a stunning 31.3% in its heartland in the rural Overijssel region and 14.3 percent in North Holland, which includes Amsterdam.
Mr Rutte, the Netherlands' longest-serving leader who has been in power since 2010, said ahead of the vote he hoped his coalition could resolve the issue.
Tessel van der Veeken, a 21-year-old student voting in The Hague, said she was "not worried but curious" about a BBB win.
Voter Michael van Heck, 69, described the farmers as a "populist party", adding that he expected a "big victory from the BBB and I hope at least stable" for Mr Rutte's VVD party.
The farmers have also won support from the global far-right, who allege, without evidence, a sinister "globalist" plot to rob farmers of their land.
But exit polls show the Dutch far-right Forum for Democracy (FvD) party, which won the last provincial elections in 2019, being virtually wiped out.
Its leader Thierry Baudet has described Russian President Vladimir Putin as a "hero" and embraced Covid-19 conspiracy theories.