The farmer, 58-year-old Udayveer Singh, and many others, have been sitting on a week-long dharna at the local administrative office. Government officials said he may have died of a cardiac arrest.
The death outraged the fellow protesters, who didn't let the authorities to move the body.
The state's BJP government led by Yogi Adityanath says it is committed to paying sugarcane dues within two weeks of purchase by the state's sugar mills. Farmers allege this has not been the case. Last week, many sugar mills of the state put up closure notices outside their main gates. The mill association said they could not afford to take any more sugarcane from farmers, as the bumper sugarcane crop was steadily depleting their profit margins.
The state government said no mill will close unless farmers sold all their sugarcane. Uttar Pradesh is one of the largest cane producers in the country.
The issue of cane dues is a central one in the campaign for the by-elections for the Kairana Lok Sabha constituency.
"Sugarcane farmers will get benefit of Rs. 5.50 on per quintal of sugarcane... Farmers' money will never get stuck with mill owners. I assure sugarcane farmers, the government is committed to their welfare," PM Modi said.
There was no reference to the death of the farmer, Udayveer Singh, prompting Congress chief Rahul Gandhi to tweet: "Sugarcane farmers of UP must be wondering when the PM comes to take credit for UPA schemes, tearing through their farms, why doesn't he think of them. Unfortunately, farmers like Udayveer, who gave their life fighting for their right, can't even do that."
Congress leader Randeep Singh Surjewala also attacked the Modi government. He said, "Udayveer lost his life during protest of sugarcane farmers. Modi-Adityanath, who came to power on promise of clearing dues of farmers in 14 days, have forgotten that dues of Rs 12,224 crore are pending and electricity bill has been raised by Rs 1,600 per month."
The Rashtriya Lok Dal -- whose candidate is looking to wrest the seat from the BJP -- has called the Yogi Adityanath government anti-farmer. Tabassum Hassan has the backing of the Congress, Akhilesh Yadav's Samajwadi Party, and unofficially, Mayawati. The election, where she has been pitched against BJP's Mriganka Singh, is seen as a test of opposition unity ahead of the 2019 Lok Sabha elections.
Get the latest election news, live updates and election schedule for Lok Sabha Elections 2019 on ndtv.com/elections. Like us on Facebook or follow us on Twitter and Instagram for updates from each of the 543 parliamentary seats for the 2019 Indian general elections. Election results will be out on May 23.