If the polling is accurate, One Nation is becoming a serious force in Australian politics.

But its considerable polling support and electoral breakthroughs in South Australia and Farrer raise a fundamental question for the conservative side of politics. Should the Coalition and One Nation form an electoral pact to defeat Labor? And what should this pact look like?

Liberal Frontbencher Tony Pasin caused a media storm recently by arguing the Coalition and One Nation “should work hand-in-glove to defeat Labor”. Pasin argues that to avoid competing with each other, the Liberals and One Nation should come to an agreement about which seats they field candidates in at the next election.

Pasin’s call comes as One Nation leader Pauline Hanson outlines her demands for any such agreement. At the same time, newly installed Liberal Party President Tony Abbott has also signalled his support for a preference deal with the right-wing populist party.

The Coalition is reckoning with how it can convert anti-Labor support into election victory. They will also be acutely aware that it is possible a strong anti-Labor vote being split between two groups on the right could help Labor maintain office at state and federal levels.

What does history tell us?

Before 1918, Australian federal elections were held under the first-past-the-post system, in which only first preferences are counted. The 1918 Swan byelection motivated conservative parties to introduce preferential voting. The aim of this reform was to reduce the impact of vote splitting, which had enabled Labor victories.

Read more: Why preferential voting is superior to first past........

© The Conversation