Winston Peters has come out swinging against National Party President Peter Goodfellow who said the party "dodged a whiskey-swilling, cigarette-smoking, double-breasted and irrational bullet", but the Acting Prime Minister would not rule out working with National despite the bad blood.

On TVNZ1's Q+A last night the Acting Prime Minister issued a warning to Mr Goodfellow, telling him it would "be the last time you give a free hit against Winston Peters and get away with it, I want to make that very clear".

"I don't think Mr Goodfellow really matters," he continued. "I went into the coalition negotiations in good faith for 11 long days, and he’s telling me it was a waste of my time when National were concerned."

Mr Goodfellow made the comments at the National Party conference over the weekend, reported NZ Herald.

When asked by host Corin Dann if he could work with National in 2020, Mr Peters said it was for his colleagues to decide.