Nepal is due to officially adopt a new Constitution that has been drawn up after years of political dispute.
According to The Daily Star, the Constitution will make the nation a secular, federal republic with seven states.
Some groups have been opposing the new Constitution as they want the country to be a Hindu nation.
Protests organised by the Tharu and Madhesi ethnic groups in the south have disrupted parts of Nepal for weeks.
At least 40 people have been killed in the unrest.