Mubarak lost the primaries to Dr Hamza Adam, a lecturer at the University for Development Studies.
He polled 273 votes while Dr Adam polled 401 to grab the party's ticket.
He also accused his opponent of money laundering, saying he has reported Dr Adam to the Bureau of National Investigations.
"As a country, we have to rethink the way we want our politics to go forward. We have seen levels of vote-buying and particularly in the Kumbungu election," he told Accra-based Citi FM.
He continued: "Interestingly I have even reported and complained to the BNI to look into the possibility of money laundering. Officially, I have reported to the BNI to look at how people could just share money like crazy so to speak just three days ago.”