NSW Deputy Premier John Barilaro has broken ranks with the state government, backing calls to cancel Sydney's New Year's Eve fireworks display amid the ongoing bushfire crisis.

Tweeting from London where he is on holiday, the NSW Nationals leader said cancelling the fireworks would be "a very easy decision", citing the fire risk along with fairness for regional areas where fireworks have been banned.

"The risk is too high and we must respect our exhausted RFS volunteers. If regional areas have had fireworks banned, then let's not have two classes of citizens. We're all in this crisis together," Mr Barilaro said.

However, City of Sydney spokeswoman Tanya Goldberg said the council was of the "firm view" the event should proceed.