BANGKOK (AP) — An ambitious rice buying program that Thailand’s ruling party hoped would aid millions of its poor rural supporters may instead help bring down the increasingly cornered government.

Hundreds of farmers from more than 10 provinces converged Thursday on the capital to demand rice payments that are several months overdue after the policy caused ruinous losses. Some have blocked three main highways in the north and the west, while a few hundred in the ruling party’s northeastern heartland protested at a provincial government hall.