Napier's Labour candidate Stuart Nash and former cabinet minister Rick Barker will square off in an "old town hall style debate" on amalgamation in the city on Friday.
Mr Nash has used the amalgamation issue to raise his profile in recent months through a prominent billboard campaign opposing the merger of the region's local authorities into a single super council.
He complained last week that vandalism attacks on the signs were politically motivated.
While he and Mr Barker have opposing views on amalgamation, it is unlikely their Friday debate will feature many political attacks on either side, as both have similar red roots.
Mr Barker was a long-serving Labour MP for Tukituki and a cabinet minister in Helen Clark's government. He is currently a Hawke's Bay regional councillor.
Debate organiser Shayne Jeffares said he was planning an "old town hall style" format where Mr Nash and Mr Barker would talk for about 15 minutes each, followed by a time for questions.
The debate will be held at the Photographers' Gallery, formerly the Red Cross Hall, on Tennyson St, at 5.30pm on Friday.
There will be a $5 door charge with the proceeds going to charity.
The debate is happening on the same day that submissions close on the Local Government Commission's draft proposal on the amalgamation plan it has put forward.
Commissioners are expected in the region next month to hear in-person feedback on the proposal, which has drawn strong opposition from many, especially in Napier, Wairoa and Central Hawke's Bay.
A public meeting in Waipawa last month, where Hastings Mayor and amalgamation supporter Lawrence Yule squared off against anti-amalgamation campaigner and Napier Mayor Bill Dalton, drew a crowd of about 200.