A frustrated Jim Chalmers has hit out at critics he accused of mounting a “scare campaign built on lies” over Federal Budget changes he agreed were “contentious”.

More than a week on from unveiling major changes to negative gearing and capital gains tax, the Treasurer was again forced to defend his promise-breaking Budget.

Since it was handed down last Tuesday night, waves of small business owners have used AI-generated images of Anthony Albanese to criticise Labor’s decision to include all asset classes in the CGT changes in what those critics are calling a “tax on success”.

The long-standing 50 per cent discount will be replaced with an inflation-index model and paired with a 30 per cent minimum tax rate on net capital gains — extending beyond just property to all investments including new shares and crypto.

Taking his national post-Budget roadshow to Perth on Thursday, Dr Chalmers said Labor “anticipated” backlash from “political opponents” but offered no indication of any potential concession.

“We understand that some of these changes are contentious. Of course they are. We anticipated that,” he said.

“We anticipated our political opponents engaging in the usual scare campaigns built on lies, and we’re seeing that too.

“But we’ve taken these difficult decisions for the right reasons. They’re the right thing to do for our economy. They’re the right thing to do by first home buyers.”

The Albanese Government had initially intended to confine the capital gains tax changes to housing, according to a report in the Australian Financial Review, but was advised by Treasury to broaden the increase to all asset classes.

Dr Chalmers had hinted post-Budget that the Government could be open to negotiation about the implementation of CGT changes for the start-up sector because of their often unique sweat equity approach — where founders take a risky pathway of shares over salary.

His vow of post-Budget “consultation” has, however, failed to quell the concerns of upset business owners who say a potential 47 per cent tax rate on real capital gains for certain firms is an attack on Australian ambition.

Less than 24 hours after more than 40 small business owners under 40 penned a scathing letter to the Prime Minister over his tax reforms, a second group of 10 female founders also issued an open letter of grievance.

The women — who include the founders of beauty and wellness, arts, fashion, public relations, and retail businesses — insisted they aren’t political operatives behind a partisan campaign as the Treasurer suggested but “women who have built businesses from the ground up”.

“We are not political operatives. We are not tax avoiders. We are women who had an idea, took a risk, and worked incredibly hard to build businesses — often while raising families at the same time,” the joint letter said.

They also hit out at former Labor prime minister Paul Keating’s overnight defence of the CGT changes and insistence that it was just “wealthy people” who are “out there now arguing”.

“We believe it is our responsibility to speak up, not only for ourselves, but for the ambitious women coming after us who deserve every opportunity to build, lead and succeed,” they stated.

“Our message to the Prime Minister is simple: Mr Albanese, we ask you to listen to female founders before proceeding with these changes.”

Mr Keating, who introduced CGT in the 80s, had blamed the Howard-era 50 per cent tax break for causing investors to flood the property market.

He dismissed the tech sector’s complaints as entrepreneurs crying foul to protect their tax privileges at the expense of regular income-earners.

“Wealthy people are out there now arguing against the Government’s change, notwithstanding the stark evidence of the price shock Howard and Costello induced. Housing prices rising from nine times income to sixteen times income over the 25 years,” Mr Keating had said.

“Punters with a big idea won’t be put off by some marginal change to the tax rate. The rush of entrepreneurial blood to the brain always dominates.”

Opposition Leader Angus Taylor also dismissed Mr Keating’s defence speaking outside the Australian Energy Producers conference in Adelaide on Thursday.

“More nonsense from Paul Keating. We’ve had a lot of nonsense,” Mr Taylor said.

“Every small business owner in this country is reconciling themselves to the fact that they have a new business partner in Anthony Albanese.

“He’s decided to become their business partner. I mean, seriously, these are small business people who are working harder than ever for less.

“And this Government wants to whack them with their toxic taxes.

“Of course Paul Keating supports it. But you know, frankly, I’m not going to be lectured to by someone who thinks that putting Australian values at the centre of our immigration policy is racist.”

Labor MPs and senators had also taken to social media in droves across the past few days to try to counter the viral AI memes of Mr Albanese — posting videos calling out the quoted “47 per cent” tax grab as “misinformation”.

“Does anyone else find it weird that a whole bunch of internet finance bros are suddenly concerned about renters?,” Housing Minister Clare O’Neill told her Instagram followers.

“I’ve watched quite a few of these videos and a lot of it is just straight up misinformation.”

Eager to leave a positive mark after a brutal week of media appearances, the Treasurer also gave the Albanese Government’s firmest commitment yet to WA’s fair share of the GST while over in Perth on Thursday.

It came after his boss had been peppered with questions about if his broken promises not to change negative gearing and CGT could also amount to a shift in position on the State’s share of of the Commonwealth’s $104b GST distribution.

Asked: “Is the current arrangement . . . WA’s ‘fair share’?” Dr Chalmers responded “Yes, it is”.

“The Prime Minister and I are huge supporters of WA getting its fair share. We’ve made that very clear. WA makes a massive contribution to the national economy,” Dr Chalmers said.

“And at every turn, my job has been to make sure that that contribution is recognised, including when it comes to making sure that WA gets a fair share of the GST.”

One Nation leader Pauline Hanson was also at the Adelaide oil and gas conference on Thursday, where she gave a speech outlining her party’s plan to increase taxes on gas.

Her plan included making the Government an equity share holder in any future gas project and scrapping the profits-based federal tax — petroleum resource rent tax — in favour of imposing a 10 per cent wellhead royalty on all offshore gas and oil production.

She also spoke of her support for gas exploration in the Great Australian Bight.

“I have a vision for this country. And I think it’s reflected in my gas policy,” she said.

“Our policy will be flexible to export surplus gas when domestic demand is satisfied, building sovereign wealth rather than undermining domestic supply projects.

“We will provide a 30 per cent rebate on genuine oil and gas exploration in Commonwealth waters. In exchange, the Commonwealth may take up to 30 per cent equity in issued production licenses.

“Any profits made on Australia’s equity ownership will be put into a sovereign wealth fund to reinvest and grow, not to be rorted by by future governments.”