The federal opposition will fight the government "every step of the way" if Labor tries to change stage three tax cuts.
Deputy Liberal Leader Sussan Ley again hit out at Prime Minister Anthony Albanese on Saturday, denying the suggestion he unequivocally ruled out changes to the legislated cuts due to come into effect in 2024.
Mr Albanese on Friday maintained the government "has not changed its position" on tax cuts.
However, Ms Ley said the Prime Minister hadn't offered Australians a guarantee they could be confident about.
Background briefings that made their way into Saturday's newspapers made it clear Labor would break its promise, she said.
"He has ministers, and he has his own Treasurer, who are clearly softening up the Australian people to walk away from these tax cuts," Ms Ley told reporters in Albury.
"He might have it in his mind that he'll redesign them slightly and still call them the stage three tax cuts ... that's absolutely not good enough.
"For him to change them he has to introduce legislation that we will fight every step of the way between now and the next election in every single corner of this country."
Ms Ley suggested she was looking to independents to bolster support to challenge any attempts to scrap other cuts.
The deputy leader challenged the government to identify "who doesn't make Labor's tax cut test" and pointed to teachers, nurses and tradies being among those who would benefit.
The cuts have been widely criticised as largely benefiting the wealthy.
Economic challenges and "ballooning expenses" were already present when Labor promised to agree to the cuts, Ms Ley said, posing the question to the government: "Is this a deception that you always had in mind ...?"
Facing questions over whether he could stand by tax cuts amid already high inflationary pressure, Mr Albanese on Friday told reporters he was informed by economics.
"No, that's me being economically literate," he said, asked if long-term fiscal pressures were being used to lay the groundwork for rescinding the cuts.
The government would continue to get on with making sure it delivered a responsible budget that acknowledged the pressures on it, Mr Albanese said.