"It's not my expectation that opposition parties will vote for him, I think it is more political than anything else," Mr Key said.
"We have the numbers so at the end of the day it's nice if the Parliament votes for the Speaker. We did have some discussions with Labour, despite what they say."
Mr Key said Mr Carter was a good choice for Speaker.
"He's had a stellar career in Parliament, he's been around for the better part of 18 years. I think he is seen as a very sensible, very sound member of Parliament. He's not overly antagonistic - I think he will make a good speaker, he will be cross that divide across the different political parties. That's one of the reasons we put him forward.
Mr Key rejected suggestions Mr Carter did not want the position.
"We wouldn't push someone in who didn't want to."
- nzherald.co.nz