Over the next six weeks, Indian voters will choose their leaders in the world’s largest-ever election. Whether citizens will opt for the ruling right-wing Bharatiya Janata Party of Prime Minister Narendra Modi or the more secular Congress Party of Rahul Gandhi remains to be seen. Where most citizens will defecate before they vote is, unfortunately, easier to predict. And while it might not seem like the most obvious metric of political success, the matter has become a symbol of contradictions at the heart of the ruling party’s platform.

It seems to be India’s most intransigent habit. Even as the country grows and flourishes, erects gleaming sky-scrapers, and churns out highly trained engineers, the government cannot get its citizens to give up open defecation. In 2015, one report estimated that 522 million Indians defecated in the open and in fields.

Prime Minister Narendra Modi and the Bharatiya Janata Party promised to change all that when he won elections in 2014. One of the party’s pledges, stated prominently in its manifesto, was the transformation of the India they inherited into a “Swachh Bharat,” or “Clean India.” Once in power, the BJP wasted no time in launching a $31 billion program to rid India of this onerous habit: Every Indian household was to have a toilet.

Last fall, while campaigning for elections which begin this week on April 11, Modi declared victory over open defecation. “The radius of rural sanitation before 2014 was approximately 38 percent, but today it is 94 percent,” Modi said. Seventy-six percent of Indian households, his government alleged in defiance of numerous critics of the program, now had a toilet.

Last year, however, a study conducted in Dharmapuri, a district in the state of Tamil Nadu that ranks the highest in the state for open defecation, offered a more pessimistic assessment. The study found that 55 percent chose to defecate in the open despite having access to a toilet, for reasons having to do either with the toilet’s construction or with personal preference or belief. The BJP’s toilet-building efforts resulted in the construction of toilets that were sub-standard, not connected to running water, or with faulty pipes or insufficiently large holes—villagers worried that the hole would fill up with excrement while they were using it. Many more said they believed using a toilet was more unhealthy and dangerous than open defecation. And while Modi has insisted that his message of taking pride in cleanliness (and hence shame in open defecation) had been successful, villagers reported no stigma associated with open defecation.