“WE have a mandate” has been the catchcry of so many prime ministers frustrated by a Senate that they can’t control.

The frustration peaked with Paul Keating, ironically referring to the Senate as “unrepresentative swill”. This same frustration has Malcolm Turnbull taking a huge risk in calling a double-dissolution election. His hope for a compliant Senate may seriously backfire.

The new electoral laws provide a brilliant opportunity for the voting system to result in an even stronger cross-bench in the Senate. Just make the major parties the last preference.

Ordinary people can now take a first or second preference risk on one or more candidates who are not from one of the major parties before moving their vote to their preferred major. The preference choice is no longer left to the backroom apparatchiks or preference whisperers – but, much more appropriately, to the voter.

Complaints about the batch of cross-bench senators from the last election are largely unfounded. No matter what their background, once elected they took the job seriously. Ricky Muir and Glenn Lazarus regularly offered thoughtful contributions. David Leyonhjelm (who I disagreed with constantly) put an interesting libertarian perspective. Additionally, the Greens have grown into a more sensible force under the leadership of Richard Di Natale and the political skills of Nick Xenophon serve as a role model for sensible cross-bench practice.

There are many examples of such senators sensibly containing the excesses of an ultra-conservative government. As much as the Liberals claim they had a mandate, this was a political party that having won government immediately broke a series of election promises that were, at least partially, responsible for getting them elected. This mandate argument is simply nonsense. It is not how our democracy works. Each piece of legislation requires majority support in both houses of parliament.

For the ACT at the upcoming Federal election it is unlikely that our Labor MPs or Senator Katy Gallagher will be under threat. Firstly, the three members have worked hard in their roles – although that has never been enough to guarantee re-election. Secondly, the Turnbull government has not been popular in Canberra and, just as under Tony Abbott, continues to reduce the public service workforce. Thirdly, there are the personal factors such as the popularity of Katy Gallagher, the intellectual contribution of Andrew Leigh and the community work of Gai Brodtmann.

Senator Zed Seselja is a different kettle of fish. He has made a contribution since becoming a senator, for example as chair of the Community Affairs Committee. However, as a proud conservative, he is still closely associated with Tony Abbott and the conservative wing of the Liberal Party. He is also the representative of a government that has slashed and continues to slash not only the public service in Canberra, but also our national iconic organisations.

Seselja’s Liberal Senate seat is vulnerable. ACT voters are used to a complex Hare-Clark optional preferential voting system used for ACT elections. Under-the-line voting for the Senate is now similar. At the last election, an under-the-line vote in NSW meant numbering more than 100 boxes in consecutive order. Any mistake, or failure to complete, made the vote invalid. For the vast majority, this was just too challenging. The easier option was to vote once above the line for the party of choice – who then distributed preferences according to the wishes of the party.

Preferential voting above the line provides a brilliant opportunity to have a Senate that holds a government accountable. In the past, the chances for the Greens or other minor parties to succeed were reduced as Canberrans could not choose their own preferences. Now there is a real prospect of having a much more meaningful vote.

The opportunity is now available for those who want to ensure that the Liberals, or the alternative Labor government, do not have a compliant Senate. Some will choose below-the-line voting, seeking very specific choices. However, an above-the-line vote that leaves the last of the preferences to the major party of choice will improve the chances of having a government appropriately held to account by the Senate playing an appropriate role as the house of review.