Welcome back to your weekly federal politics update, where Courtney Gould gets you up to speed on the happenings from Parliament House.

After failing to catch anyone by surprise with the budget, Anthony Albanese had another trick up his sleeve.

The prime minister stepped into the courtyard on Thursday with an unlikely new friend by his side: Tasmanian senator Tammy Tyrrell, adding another defector to Labor's ranks.

"People across Tasmania know her as a fighter," Albanese said. Tyrrell made no apologies for trading the crossbench for a place in the good ship government, declaring she was "proud to be a Labor girl".

Tyrrell was elected to parliament in 2022 under the Jacqui Lambie Network banner, vanquishing long-time Liberal Eric Abetz. Before her election, she was Lambie's office manager. The pair were a team, she said, until they had a falling out two years ago and she left for the crossbench.

The Nationals approached her last year. At the time, she said jumping into a party relationship would compromise her ability to "stay true to [her] moral compass".

"I'd rather just stay as a single divorcee over here," she'd told The Australian.

The Easter eggs were there, if you were looking. Tyrrell posted to her socials a photo of her wearing a red blazer with a statement about how this was the budget, handed down a day earlier, that we "had to have". Her comment sections were immediately filled with people complaining about her switching sides, again.

Labor's union with Tyrrell hands it an additional number in the upper house, up from 29 senators to 30. She's the second to join Labor in the past year, after former Green Dorinda Cox.

It doesn't materially change the dynamic at play when it comes to getting legislation over the line (Tyrrell admitted herself she had frequently voted with Labor in the past).

But it's a symbolic win for Albanese, who taunted the opposition in Question Time that his caucus was growing, while the Coalition's was shrinking.

Tyrrell said she needed to find a "fit". What went unsaid was that finding her third political home in four years was as much about the electoral reality than a desire to join the Labor caucus.

A rise in One Nation support adds another layer to the dark arts of Senate preference counts. Lambie herself held off a challenge from Pauline Hanson's daughter Lee last year. It took weeks for the preferences to be counted. In the end, Lambie's high profile got her over the line in fifth spot.

That high profile is a luxury Tyrrell does not have.

So instead of duking it out with Hanson junior, it's expected Tyrrell will face a pre-selection fight against longtime Labor senator Helen Polley.

Polley has called the Senate home since 2004 and is likely best known online for her videos that often feature her beloved George Foreman grill (and that one time she repeatedly called Dan Repacholi "Dan Ravioli").

Tyrrell has been a vocal critic of the government's social media and vaping ban. She's also no fan of a project Albanese has long supported: the contentious Macquarie Point stadium. A gas export tax, which Albanese killed off pre-budget, was also in her sights.

The timing of her defection in the same week (and even in the same press conference) as Albanese was under pressure for breaking a promise of his own, was interesting.

Treasurer Jim Chalmers's fifth budget headline was the confirmation of the worst-kept secret: Labor was dusting off its plans on negative gearing, and the capital gains tax discount, despite promising not to.

Chalmers said he'd rather defend a shift in policy than "leave a broken status quo in place to do more damage". It's an admirable goal.

With one eye on what's occurring in the UK with Nigel Farrage and Reform, Labor made the decision not to stand still. As the PM argued in his post-budget sell, the government changes its mind all the time — just look at the shift in thinking on the fuel excise.

Success in reworking the stage three tax cuts and superannuation tax breaks (both without an election mandate to do so) has emboldened Labor. It's made the calculation that now, in the middle of its second term, people will forgive them — especially if they get their hands on the tax cuts the budget foreshadowed as potential election sweetener in 18 months' time.

And sure, they might. But the problem is that doing this now, and the way it's done so, sets up an irrefutable pattern of how they go about it.

Back in 2023, it was the superannuation tax breaks. That was signposted by a speech and the release of a re-vamped Tax Expenditures and Insights Statement (the document required by the charter of budget honesty to outline foregone revenue).

Every man and his dog knew the government was looking at retooling the stage three tax cuts. The kite was flown, and shot down, many times before Albanese confirmed it at the National Press Club early in 2024.

The changes to negative gearing and the capital gains tax discount follow the same thread. Treasury modelled the data. There was a quick senate inquiry, leaks to the media, and bam, there it was.

Even the language used doesn't change. On stage three, Albanese declared he was being up-front, and he wasn't prepared to kick the can down the road. It was the same language he used as went from interview to interview to sell why this needed to happen now.

How can the electorate believe the government next time they rule out anything, such as an increase in the size of parliament or say the other part of their failed 2019 policy — franking credits.

During the budget lock-up last year, then-Liberal leader Peter Dutton decided the opposition could not support Labor's $17 billion tax cuts. He vowed to repeal them if the Coalition won the election. You know how that story ends.

The Coalition will not support the housing tax overhaul. Watching Question Time this week, one got the sense that was exactly what the prime minister was hoping for. He drew a link between last year's decision and now as if to say, "millennials and zoomers, they don't care".

Opposition Leader Angus Taylor has retorted that it's an attack on aspiration and is pulling up the ladder for that same cohort to build wealth through property like their parents before them.

Taylor will get his chance to deliver his first budget reply this evening. He'll unveil his proposal to tie migration to housing, and reserve access to welfare, including the NDIS, for Australian citizens.

But his big play involves a plan to automatically index income tax brackets to keep up with inflation. Ahead of the speech, Taylor would not say how much the plan would cost.

No doubt it's a bold move and one Chalmers ruled out considering the day prior, setting up a differentiation come election time.

But with One Nation breathing down his neck, Taylor has no choice. It's all or nothing, or to use his own words, "change or die".

The populist wave is a threat for everyone. And it appears, as it laps at the doors of the major parties, the election campaign is never really over.