Any council that tries to move Australia Day citizenship ceremonies from January 26 will be punished, Home Affairs Minister Peter Dutton says.
The federal government has threatened to strip several NSW councils of the right to hold Australia Day citizenship ceremonies amid plans to hold them a day earlier.
Hawkesbury City is reportedly considering holding its ceremonies on the evening of January 25 because of the daytime heat.
Kempsey and Bellingen shire councils have similar plans, according to Macquarie Media.
Home Affairs Minister Peter Dutton suggested the move was political rather than weather related and warned them against changing the day.
"I don't care whether people are seeking to move it in an obvious way or playing games - the intent is very clear," he told Sydney's 2GB on Thursday.
"Australians don't want councils playing politics with these issues."
Mr Dutton said ratepayers expected Australia Day to be "respectful" to those new citizens who consider it one of the proudest days of their lives.
"We're not going to have that disrupted by this nonsense," he said.
"The rules are pretty clear. If they're not going to abide by it, then they'll find themselves without the ability to conduct the ceremony."
Last month, Byron Shire Council backed down on its plan to move its citizenship ceremonies from January 26 after threats from Prime Minister Scott Morrison.
He called the move "indulgent self-loathing".
Citizenship Minister David Coleman later wrote to all council mayors to reinforce that citizenship ceremonies should be apolitical, bipartisan, non-commercial and secular.