Choubey has publicly declared that the alliance would prove suicidal for the BJP. Choubey is also a known supporter of Modi.
Giriraj Singh and Choubey, however, claimed they did not attend the rally due to personal reasons.
"My brother met with an accident. So I postponed my visit to Muzaffarpur," Giriraj Singh told IANS. Choubey said he skipped the rally due to health reasons.
In the 2009 Lok Sabha polls, the BJP won 12 of the 40 seats while the Janata Dal-United, its ally, bagged 20 seats. The alliance of the two parties has since collapsed.