The group's national director, Paul Oosting, said it would be launching a billboard criticising the government for failing to go after corporate tax cheats while it attacked ordinary people over "false" debt claims.
The billboard would be placed on the lawns of Parliament House on Friday, he said.
GetUp has been extremely active in campaigning against the Centrelink move to recover what it claims are over-payments to welfare recipients.
They were given up to three weeks to explain, or told they would face an adverse assessment and have to pay a recovery fee of 10%.
A large proportion of these letters turned out to be wrong because they were sent by an automated system that had not calculated the amounts correctly.
Earlier this month, the Senate voted to hold an inquiry into the debt recovery programme.
Oosting said: "The Turnbull government's priorities could not be clearer. They want to extort money from people who are working hard, just to keep their heads above water, while failing to stand up to tax-cheating offshore corporations.
"In 2014-15 alone, 679 major corporations paid not one cent in tax on $462 billion in revenue. That's billions of dollars that isn't going to Australian schools and hospitals."
He accused Turnbull of harassing ordinary people who were just trying to lead their lives, while standing by companies which shipped billions in profits to offshore tax hideaways.
"The Turnbull Government is attacking tens of thousands of Australians per week with threatening letters about false debts," Oosting claimed. "Reports are that pensioners, families and people with disabilities are next.
"The changes to the onerous review process announced by Minister Alan Tudge last night are an admission of what a car wreck this programme is. Now he's trying to throw a new coat of paint on a wrecked car, but it doesn't change the fundamental fact that their faulty system is sending out tens of thousands of fraudulent debt threats."
Oosting said the automated debt programme should be scrapped immediately.
"The fate of our pensioners and families shouldn't be decided by the Turnbull Government's faulty computer program. Australians deserve a human being on the other end of the line," he said.
"Yet we see no action against the multinational dirty energy companies robbing us of the tax they owe.
"In just one year Chevron generated more than $3 billion in revenue with our natural resources and paid zero dollars in tax. And if things don't change, they're projected to pay no tax on more than $42 billion in revenue over the next ten years. That's a sick joke."
More than 72,000 people have signed a petition calling on the government to stop the automated Centrelink debt letter threats immediately.