Mr Emeka tendered his resignation onWednesday after President Muhammadu Buhari issued a directive for all ministers and aides seeking elective offices next year to resign.
Mr Nwajiuba is seeking the presidential nomination of the ruling qAll Progressives Congress in the upcoming general elections.
Others expected to resign from the cabinet include Attorney-General Abubakar Malami, transport minister Rotimi Amaechi, Niger-Delta minister, Godswill Akpabio, labour minister Chris Ngige, science and technology minister Ogbonnaya Onu, mines minister Uche Ogar and women affairs minister Pauline Tallen.