Achonu polled 134 votes to beat his closest rival Major General Jack Ogunewe who scored 121.

Senator Achonu was elected into the Senate of the Federal Republic of Nigeria in 2015 to represent Imo North on the platform of the People’s Democratic Party (PDP).

However, in October 2015, the Tribunal sitting in Owerri upturned his election at the instance of the candidate of Accord Party, Mrs. Rita Ibemere Okoroafor challenging the unlawful exclusion of her party logo and symbol from the customized ballot paper for her senatorial zone and further claimed that the unlawful exclusion vitiated substantial compliance of the said election with the provisions of the Electoral Act 2010 as amended.

The tribunal ruled that the Accord Party candidate proved her case beyond all reasonable doubt, and ordered a fresh election. The Appeal Court concurred in December 2015.

Achonu lost to the candidate of the All Progressives Congress (APC) Benjamin Uwajumogu in the fresh election conducted in 2016.

Achonu hails from Ehime Mbaino LGA.