Mahato began his political career in 1990. In the 1994 parliamentary elections, he contested from
Sarlahi 2 as a candidate of the
Nepal Sadbhavana Party finishing second with 10,173 votes. In the 1999 elections, he won the seat with 14,750 votes, defeating former Prime Minister Surya Bahadur Thapa of the
Rastriya Prajatantra Party. In 2007, Mahato split from the
Nepal Sadbhavana Party (Anandidevi) and formed his own party which he later named the
Sadbhavana Party. Over the years, he joined several parties including the
Rastriya Janata Party,
Janata Samajbadi Party and
Loktantrik Samajbadi Party. In April 2008, Mahato was elected from
Sarlahi 4 in the Constituent Assembly election. However, he lost the seat in the 2013 election to
Mahendra Rai Yadav of the
Terai Madhesh Sadbhavana Party. Under proportional representation, his wife Sahil Devi Mahato was nominated to the Assembly. Mahato has been a prominent advocate for Madhesi rights, expressing opposition to provisions in Nepal’s draft constitution that he viewed as discriminatory against the Madhesi community. == Personal life ==