Grattan on Friday: Aston byelection will test Peter Dutton's ability to campaign on Victoria's tough terrain

The Melbourne outer suburban seat of Aston, set for a byelection after former Liberal minister Alan Tudge’s resignation, has already made its mark on history.

The Howard government was on the ropes in 2001 when Aston’s then Liberal MP, Peter Nugent, died suddenly of a heart attack. The July byelection was hard-fought but the Liberals hung on. There were other, more important, events on the road to John Howard’s November election win, but the Aston victory has gone down in the narrative as a crucial turning point.

Now Peter Dutton faces his own Aston test, which comes with risks and opportunities.

The risks for the opposition leader are obvious. Dutton’s natural stomping ground is Queensland. Victorians don’t much like him. He didn’t venture into the recent state election. A loss would be catastrophic for him.

Dutton will be relieved Josh Frydenberg doesn’t have his eye on Aston. If the former treasurer were the candidate, the media chatter from now until the byelection would be about the implications for the Liberal leadership if Frydenberg were back in the parliament.

Frydenberg’s decision is wise. Given the volatility of politics these days, he couldn’t be certain of winning and if he did, the resulting destabilisation in the Liberals would only benefit Labor. It’s better for Frydenberg to wait and re-contest Kooyong, where teal independent Monique Ryan might be vulnerable next time.

While Dutton has most on the line in Aston, the byelection (likely to be after Easter, in April) will in part give an early “real time” reading on whether cost-of-living issues are harming the Albanese government. This is despite the fact Aston, according to ABC election analyst Antony Green, is no longer the mortgage-belt seat of old.

Aston voters showed their disapproval of Tudge, Scott Morrison and the Liberals last year with a swing of more than 7%, leaving the seat on a 2.8% margin. Green observes that one would expect it to revert to a more comfortable position on the Liberal spectrum.

But in politics perceptions matter. If Dutton secured a decent swing after a strong “cost of living” campaign it would be a morale boost for the Liberals and shine attention on the potential damage that issue – not yet hitting Labor in the polls – could do in vulnerable government seats.

Labor knows the financial squeeze on families is a slow burn. ALP national secretary Paul Erickson, in a briefing this week, told caucus members the most important issue voters want the federal government to focus on is helping households with their cost of living.

Read more: Alan Tudge quits parliament, prompting byelection test for Peter Dutton

The Tudge resignation was the second shock of 2023’s first federal parliamentary week.

Senator Lidia Thorpe’s jump from Greens to crossbench has made the Senate much trickier for the government to manage.

The biggest loser immediately is ACT independent David Pocock. Until this week, Pocock had been Labor’s automatic port of call for the single vote it needed from the non-Green crossbench to pass legislation supported by the Greens but opposed by the Coalition.

The government and Pocock have had a cosy relationship. He’s a progressive, broadly aligned with Labor in his views.

He’s not difficult to negotiate with, although he’s wanted his political money’s worth, so has extracted some concessions in exchange for his vote. One was important. The prime minister agreed to set up a committee to report publicly before each budget on the adequacy of income support payments. Jim Chalmers will soon be wrestling with the first of those reports.

With Thorpe’s defection the government requires two non-Greens crossbenchers to secure contested legislation (although Thorpe says she will vote with the Greens on climate bills).

Pocock says the change in the Senate’s makeup “increases all of our capacity to push the government for more ambition and better outcomes on contested legislation”.

Read more: Grattan on Friday: David Pocock has only just arrived in the Senate and now he's negotiating with the PM

In fact, the net effect is to reduce his capacity and boost that of Tasmanian crossbencher Jacqui Lambie, who commands two votes.

Labor can’t in practical terms look to Pauline Hanson and her Senate offsider, Malcolm Roberts, or Victorian UAP senator Ralph Babet. Thorpe will likely be a challenge, and could only provide one vote anyway.

Lambie and her colleague, Tammy Tyrrell, can give the government the numbers it needs on particular pieces of legislation. From the government’s point of view, this would means just a single negotiation (as distinct from the double negotiation needed to get, say, Pocock and Thorpe).

Lambie will be delighted to be back at the centre of things. In recent months she has been overshadowed by Pocock.

But in negotiations she can be difficult, demanding and at times shrill, and is at odds with Labor on some issues, such as aspects of industrial relations. She has been questioning on the Voice. The government may try to work through the easier-going Tyrrell where it can.

Apart from legislation, the altered numbers give the Senate more scope for making trouble for the government. The Coalition and the seven non-Green crossbenchers now have the numbers to form an absolute majority.

Though Thorpe has dealt herself into the Senate play, there will be constraints on her. She’d presumably find it hard in ordinary circumstances to vote with the Coalition on legislation, and if she abstains, the government will be back to needing only a single extra vote to pass contested bills (cue Pocock).

Read more: Lidia Thorpe's defection from the Greens will make passing legislation harder for Labor

Thorpe’s defection has also increased the ability of the opposition to exert influence in the legislative process. Given the greater Senate uncertainty, the government may on occasion prefer to wrangle the Coalition rather than the crossbenchers.

We saw that this week when Anthony Albanese agreed to Dutton’s call to change the referendum machinery bill, so the usual pamphlet outlining the yes and no cases would be sent out.

The concession is welcome. The government’s argument that the pamphlet is unnecessary because everything is on the internet was spurious, not least because voters in remote communities, who have a special interest in the Voice, probably have poor access to the internet.

Meanwhile the Senate this week delivered the government a first significant parliamentary defeat.

In a vote that saw even the Greens deserting Labor, the Senate disallowed its removal of the requirement for superannuation funds to provide detailed information on how they spend members’ money.

The Senate vote, on a motion lodged by Lambie, was a victory for transparency – something Labor professes to support. As the late Don Chipp, founder of the long-gone Australian Democrats might have said, it was a case of the Senate, and particularly the crossbench, “keeping the bastards honest”.