Mr Birrell was acting party whip, a position that requires him to count the votes and announce the outcome.
Federal Nationals members elected Member for Maranoa David Littleproud as party leader, ahead of the challenger, Queensland senator Matt Canavan, who failed to garner sufficient support after positioning himself as an agent of change.
Member for Page Kevin Hogan was elected deputy.
A fresh deputy was needed after the party’s former second-in-command Perin Davey lost her Senate seat on May 3.
Mr Birrell was following party protocols, and not disclosing the voting details this week.
“I’ll take them to my grave,” Mr Birrell quipped.
Personally, he said he was happy with the outcome of the vote and believed Mr Littleproud had done a good job.
“I’ve had a lot of valuable discussions with him,” he said.
As far as Senator Canavan went, Mr Birrell acknowledged his experience, but said he saw some things differently to the Queenslander.
In the post-election wash-up, Mr Birrell noted the ALP government’s reshuffle had seen Tanya Plibersek lose the environment portfolio, in favour of Murray Watt.
Mr Birrell expected the switch might be favourable on water issues.
“I don’t agree with Murray Watt on everything, but we’ve been able to talk through some issues,” he said.
“I have a good working relationship with Murray Watt.”