Bill English says Winston Peters has always performed a "maverick role" in politics - a description Peters has labelled unwise.
The National Party leader made the comment to Radio New Zealand's Guyon Espiner this morning as he discussed the state of coalition talks with New Zealand First.
English said he had known Peters since 1990. Their relationship had swung between "combative" and "sociable" but he respected Peters for his "maverick role" in Parliament.
"That's always been a bit of his brand."
Speaking in Whangarei to 1 News, Peters - who is set to begin negotiations with English over a potential coalition government - said the comment "[wasn't] a very smart thing to say".
Peters and his partner Jan Trotman headed north to their Whananaki property for a spot of fishing post-election.
However, Peters returned to Auckland today ahead of discussions with his team over potential coalition negotiations, Fairfax reported.
He has had a difficult history with English, who helped oust him from the National caucus in 1991. But Peters told 1 News that "the problem with politics is you have to deal with reality".
"Though some things may be total anathema to you in terms of history, you've got to do what the country needs you to do."
Peters has indicated he will not make a final decision before October 7 when the results of special votes are known, but told 1 News talks could start earlier.
"What we'll be saying is possibly we need to get some preliminary things out of the way with both sides, I'd imagine."
Peters said those claiming he would hold the country to ransom were "jaundiced and mindless and don't care a hoot about the facts".
He had not yet spoken with English or Labour leader Jacinda Ardern but his chief of staff had spoken with both of theirs.
English this morning told RNZ he expected negotiations to be constructive but "tense".
He wouldn't publicly rule anything out in the negotiations with Peters - except for handing over the prime ministership.