The accident took place on Sunday near Phugana bus stand on the Meerut-Karnal Highway as the driver tried to avoid a car coming from the opposite direction, they said.
"The government is disallowing use of tractor trolley for conveyance as part of a well planned conspiracy so that tractors are not used in farmers' agitations," the said the BKU leader.
Earlier on Saturday, 26 people were killed in a road accident in Kanpur when a tractor-trolley carrying devotees returning from Unnao overturned.
The circular issued by the government says that those found flouting the rules would be slapped with a penalty of Rs 10,000.
Sarh police station in-charge Anand Kumar was suspended due to a delay in rushing the police force at the accident spot.
The tractor-trolley, carrying about 50 people, was on its way to Ghatampur after the passengers attended a "mundan" ceremony at the Chandrika Devi temple in Fatehpur, the official said.
37 out of the 47 people who were travelling in the vehicle sustained injuries; they were on their way to attend the ceremony at a Durga Devi temple in Unnaee village.