Labour leader David Shearer will not rule out putting another MP forward for the role of Speaker in protest at the Government's failure to consult with Labour over its choice of David Carter for the job.
Labour's caucus will discuss the role this morning after Prime Minister John Key announced the Government was putting Mr Carter forward to replace Lockwood Smith.
The Speaker will be elected in Parliament on Thursday and the Government is almost certain to gets its choice through.
Mr Shearer said unless Labour was consulted before Thursday "I can't see this going as smoothly as it has in the past".
Caucus would consider today what it would do, he said.
"We haven't had discussions about who might be an alternative. If they want to buy a fight over this, this is the way they are going."
Mr Shearer said the Government had broken with convention by failing to discuss its choice for Speaker with Labour. He was also critical of Mr Carter, saying he did not appear to have any enthusiasm for the role or the knowledge of Parliament's rules.
Mr Shearer said if Parliament was to function well, there had to be confidence in the Speaker. Labour had been consulted before Mr Smith's election in 2008.
"We have confidence in Lockwood Smith. You need a Speaker who has confidence across the House, David Carter doesn't seem to have any real enthusiasm for the job. We don't think he's the sort of person who really has a good understanding of the rules."
He rejected Mr Key's claim that there were informal approaches to Labour, which ended after Mr Shearer made it clear publicly that he preferred Maurice Williamson over Mr Carter.
Mr Carter was asked about the job numerous times last year after speculation he would prefer to stay on as a minister. Mr Carter had said he was happy to do whatever job the Prime Minister wanted him to do.
- Claire Trevett of the New Zealand Herald