A former National leader says deals should be done -- to avoid the National leadership coming down to a caucus vote tomorrow

Christopher Luxon appears to have made up his mind to run for the leadership -- and is thought to have the edge on Simon Bridges in terms of numbers.

It means the pair could face off in a leadership vote at tomorrow's caucus meeting.

But former National leader Don Brash says Luxon would be better off striking a deal to avoid dividing the caucus with a vote.

He says if Luxon has a strong majority position in the caucus, then it's only logical to do with a deal with Bridges.