The Nigerian Bar Association on Thursday rejected the N5, 000 note proposed by the Central Bank of Nigeria, saying legal action may be taken to stop it.
NBA President, Joseph Daudu (SAN), in a speech during the association's Annual General Meeting (AGM) in Abuja, said the policy could "damage the lives of Nigerians."
He described it as "a shallow scheme."
Meanwhile, protesting lawyers who had barricaded the gate of the venue for about two hours in the morning were eventually allowed in.
Security agents stopped them because they did not wear the conference tag, meaning they did not pay the fees.
Daudu admitted that the AGM is "an open meeting for all lawyers and all lawyers are welcome."
"The fee-paying part of the Annual General Conference ended with the annual bar dinner on Wednesday night," he said.
On the proposed N5, 000 note, Daudu said introducing it would weaken the naira and promote corruption.
"The looming danger is that using large bills will devalue the naira.
"It will promote money laundering and massive monetary inducement in the next general election.
"It's also against the cash-lite policy of the NBA, and is disparate to what obtains elsewhere.
"If it has to be litigated against, so be it.
"The CBN should not be allowed to damage the lives of Nigerians through shallow schemes such as this," Daudu said.
The occasion marked Daudu's last major assignment as he hands over to a new administration led by Okey Wali (SAN).
"If I've offended anybody in the course of the two years I have been in office, I apologise.
"I have also forgiven those who needlessly offended me. Let us all forge ahead to move the association forward," he said.