"It does not behove a union minister to speak in such a language...Its objectionable remarks," Kushwaha, President Rashtriya Lok Samata Party (RLSP), an ally of BJP, told reporters.
RLSP does not approve of such comments by any personality, he said.
Questioned over the demand for Singh's resignation, Kushwaha said he was not competent to comment on the issue, adding, BJP central leadership would dwell on the issue.
Asked if the incident would have an impact in the upcoming Bihar elections, Kushwaha, who is Union Minister of State for Human Resources Development (HRD), answered in negative.
Singh had also mocked Rahul Gandhi's absence from the political scene and likened it to the "missing Malaysian airliner".
