The 62-year-old BJP MP from Nawada had caused some embarrassment to the party during the Lok Sabha poll campaign when he suggested that Muslims unhappy with Modi should go to Pakistan, forcing the party's prime ministerial candidate to issue a rebuke.
But Singh, a first time MP, is also one of the early Modi loyalists in the party and often took on the then Bihar Chief Minister Nitish Kumar over his antipathy towards Modi despite being a member of Kumar's cabinet.
It is believed that despite his proclivity to make unwarranted statements, he enjoys the Prime Minister's affection due to his unqualified support for Modi when the party was still divided over whether to elevate him as its prime ministerial candidate or not.
When reports were rife that Singh was unhappy over his candidature from Nawada instead of Begusarai, which was considered a safer seat for BJP, Modi held a rally in the constituency and embraced him at the dais, while telling the crowd that he was his man to serve Nawada.
The first-time MP, and earlier a Legislative Council member in Bihar, has special interest in agricultural practices and animal husbandry.
With the elevation of Singh, BJP hopes to rally influential Bhumihars around it as Bihar goes to Assembly polls next year. Though Union minister Manoj Sinha is also a Bhumihar, he is from UP and has little influence in Bihar.