It was sufficient to energise the union movement and helped to sweep the government from office. Howard lost his seat and industrial relations reform became the political equivalent of that unwelcome family relative at Christmas. More than a decade on, the Senate and its make-up after the looming federal election is again on the minds of the major parties. The results of the double-dissolution election of 2016, which delivered an upper house that had more than a passing resemblance to a certain cantina on Tatooine, will be washed through at this year's poll. Excluding the Territory senators, the the Coalition has 13 seats, the ALP 11 and the Greens six to defend. Also up for election are minor party players including Derryn Hinch (Victoria), NSW senator Brian Burston (first One Nation, now with Clive Palmer's reimagined United Australia Party), WA One Nation senator Peter Georgiou and Queensland's right-wing lightning rod Fraser Anning.

The LDP's David Leyonhjelm was due to face voters, but needing a quota of 14.29 per cent to remain a senator, he is headed to the NSW election, where he needs to secure 4.55 per cent of the vote. Fraser Anning's days appear to be numbered. Credit:AAP Aside from Hinch, who snared three upper house seats at the Victorian election last month, the chances of Burston, Georgiou and Anning getting back at this election are long. Which paves the way for the major parties to increase their senatorial numbers. In NSW Labor has just one senator up for re-election, suggesting it will nab at least another and perhaps a second at the expense of the NSW Greens. The Coalition also believes it could grab the spots left by Leyonhjelm and Burston.

In Queensland the position occupied by Anning was originally won by Malcolm Roberts on behalf of One Nation. Senator Sarah Hanson-Young is fighting for her political career. Credit:Alex Ellinghausen While Hanson has a large popular following, there are questions over whether this will be sufficient to get Roberts (who is again standing for One Nation) back into the Senate. Anning's political career is likely to end. South Australia could shake-up the upper house in a profound way. The Liberal Party is defending three positions, the ALP just one, while high-profile Green Sarah Hanson-Young is fighting for her political career alongside former Xenophon and now independent senator Tim Storer.

No one believes the Xenophon/Centre Alliance team is polling as well as it did at the 2016 election, when it secured almost 22 per cent of the vote. Labor, which is defending just one position, is all but guaranteed of picking up an extra Senate spot. The Liberal Party – which technically collected two seats but then added the Family First spot claimed by Bob Day before the High Court tossed him out in favour of Lucy Gichuhi – is placed to keep its three. Hanson-Young, whose high profile will be an advantage given the end-of-ticket voting, still faces a battle to remain in the Senate. Over in WA, Hanson is defending her one remaining senator, Georgiou. Again, the 14.29 per cent quota might be too big a hurdle for Georgiou, which could allow the Liberal Party to pick up an important spot.

Last year's "super Saturday" byelections in Fremantle and Perth also pointed to a softness in the Greens support that has some in the ALP believing the seat occupied by Jordon Steele-John could be vulnerable. Lisa Singh needs another electoral miracle in Tasmania. Credit:Peter Mathew Tasmania, which in 2016 saw Labor's Lisa Singh (successfully) and Liberal Richard Colbeck (unsuccessfully) use their personal standing to win large numbers of votes, will also have a major impact on the shape of the Senate. Singh has, again, been pushed down to a spot thought unwinnable. She grabbed more than 6 per cent of the primary vote last time around, but without a flow of preferences it's going to be tough to pull off another electoral miracle. Colbeck is top of the Liberal ticket and is likely to be joined by Claire Chandler.

Also running is Jacqui Lambie, up against former running mate Steven Martin, who switched to the National Party after he found himself in the upper house. Martin's return is unlikely while Lambie will face a battle. The Greens' Nick McKim, who got back to the Senate in 2016 by only 141 votes over One Nation, may find it slightly easier this time. In Victoria, much hinges on whether Hinch – who had the prime position on the ballot last election – can repeat his 2016 effort. Again, the larger quota at a normal half-Senate election is a major hurdle. Once the dust settles, both the Coalition and the Labor Party could be up to three seats better off. Much hinges on the relative performance of Hinch, Lambie, the Greens, One Nation and the Centre Alliance. Malcolm Turnbull's plan to clear out the noise of the Senate may work, only one election later than expected. Yet that ignores the lessons of Howard's 2004 majority.

The left-leaning Australia Institute this week released polling of Australians' views towards the Senate, and the results suggest people want the upper house to continue acting as a handbrake on the government of the day. Almost three-quarters of those polled agreed the Senate should "pass or block legislation on its merits". Two-thirds agreed that when governments negotiate with other parties, it leads to better laws, while a similar number agreed it was bad for the nation when a single party controls both the Senate and the House. While the major parties eye off strengthening their position in the Senate, voters look like they enjoy an upper house cantina. Shane Wright is a senior columnist.