Scott Morrison has rebuffed Bill Shorten's claim the government is politicising Australia Day with a plan to force councils to have citizenship ceremonies on January 26.
The prime minister hit back at the Labor leader for not immediately backing the move which he says is common sense.
"I think Bill Shorten is having a cop-out on this," Mr Morrison told reporters in the Northern Territory.
Forcing councils to have the ceremonies on Australia Day comes after a handful of municipalities voted to move citizenship events out of respect for indigenous people.
"If some councils as we've seen want to play games, well, you don't have to run citizenship ceremonies, other arrangements will be made," the prime minister said.
"But we will not undermine Australia's national day."
A strict dress code for ceremonies will also be introduced banning board shorts and thongs.
"I'm a prime minister for standards," Mr Morrison said.
With Australia Day less than two weeks away, national debate is again set to flare on the most appropriate date.
Labor leader Bill Shorten said didn't rule out supporting the plan, but guaranteed he would keep the public holiday if in government.
"You sort of know when Australia Day's coming up don't you, when a couple of weeks before we get the annual conservative outing to put politics into Australia Day," Mr Shorten told reporters in Melbourne on Sunday.
"It's what the conservatives do to keep their base happy."
Under changes to the Australian Citizenship Ceremonies Code to be introduced in the first half of 2019, councils must hold a second citizenship ceremony on September 17 - Australian Citizenship Day.
Australian Local Government Association president David O'Loughlin said some councils had events the night before because of heat.
"The federal government's strong focus on drawing a link between Australia Day and citizenship ceremonies is bizarre," Cr O'Loughlin said.
Immigration Minister David Coleman said the move would ensure every person being given citizenship had the chance to do so on January 26.
"Councils will no longer be able to say no to Australia Day," he told reporters in Queensland.
NSW Premier Gladys Berejiklian said January 26 was the natural day for ceremonies to be staged.
But acting Victorian Premier James Merlino was more sceptical.
"I think this is more to do with the federal election than with the Morrison government respecting our country," he said.