Prime Minister John Key has scorned Winston Peters' claim that he's using the appointment of a new governor-general to distract public attention from the flag referendum.
The NZ First leader says a serious constitutional appointment was "sullied by the prime minister's media manipulation" and the timing wasn't accidental.
The flag referendum ends on Thursday and an interim result will be announced that night.
"Unfortunately for him, he probably doesn't understand how the timetable works," Mr Key told reporters.
"The announcement was always going to be around this time."
Mr Peters also believes Mr Key is attending next week's conference in Washington on countering the threat of nuclear terrorism so he can "escape further embarrassment".
The final referendum result will be announced on March 30, and Mr Key will be in Washington from March 29 to April 1.
"It was really lovely of President Obama to organise the nuclear security summit around the referendum," Mr Key said.
"I suspect we will know the result on Thursday night, and I will be in the country for that."
Mr Key supports changing to the silver fern flag designed by Kyle Lockwood.
Mr Peters has campaigned to keep the current flag and says the referendum is a waste of money.
Opinion polls show a strong majority in favour of keeping the current flag.