Governments that overstep their political mandate do so at their peril, and the backlash is often expressed in by-elections. Analysis by Mr Alastair Harkness and Associate Professor Brian Costar of Monash University's Politics department.

Although usually confined to issues of local significance, by-elections can result in the downfall of a government, such as occurred in Queensland in early 1996. The Goss Labor Government won the general election in 1995 with a single-seat majority, but subsequently lost a by-election in the Townsville-based seat of Mundingburra, brought about by a successful appeal to the Court of Disputed Returns.

The sole independent member of the unicameral Queensland Parliament then found herself in the position of determining the fate of the government and, eventually, delivered her vote of confidence to the Borbidge-led National/Liberal Party Opposition. This raised the question of what impact by-elections have on the doctrine of the mandate.

The meaning of mandate

There is very little certainty about what precisely a mandate confers upon an elected government, but it is generally accepted that the mandate doctrine involves two aspects.

First, by virtue of being elected with a majority of seats in the lower house, governments are entitled to perform day-to-day government executive functions. Second, and more contentiously, governments may claim a specific mandate to implement policies outlined in their electoral manifesto. Some assert that a government will abide by the terms of its mandate by honouring its promises, and by not exceeding public expectations of what it said it would and would not do.

An obvious virtue of by-elections is that they provide an opportunity for the mood of the electorate to be expressed between general election and communicated to the party in power and to the oppositions.

Such would not have been possible had Victorian Premier Mr Jeff Kennett's suggestion of early 1996 been legislated -- that by-elections not be held where a government held a greater than five-seat parliamentary majority.

By-election results can lead governments to claim a reaffirmed mandate, or for oppositions to demonstrate a diminished mandate. The former occurred when the Howard Government defended the Sydney seat of Lindsay at a by-election in October 1996. Labor, in Victoria, may well claim that the Kennett Government has a diminished mandate as a result of the Mitcham by-election in the eastern suburbs of Melbourne.

In Mitcham, the Kennett Government was on the receiving end of the second-largest anti-government swing in modern Victorian politics. While by-elections only change a mandate if the government loses its majority, and do not confer a fresh mandate, this particular result holds an important message for the Victorian Premier.

Despite the Liberal candidate in Mitcham desperately trying to focus on local issues alone, the campaign was largely seen as a referendum on the key state-wide issues of the government's changes to the role of the Auditor-General and to WorkCover, and, to a lesser extent, on gambling, as well as on the Premier's leadership style itself.

Following its massive loss in Mitcham, the Liberal Party machine went into damage control. State director Dr Peter Pogiolli argued that voters realised that even a strong protest vote would not lead to a change of government. Other senior Liberals have put the loss down to poor communication of the government's reforms.

Dr Pogiolli also noted that only one quarter of the votes lost by the Liberal Party transferred directly to the Labor Party. Such an outcome was to be expected with such a large field of candidates, compared to the four who contested the previous election.

The fact remains that just one quarter of the electors placed the Liberal candidate ahead of his Labor counterpart. This demonstrates that the electors of Mitcham were well aware of the nature of a preferential voting system.

This by-election has provided a contemporary re-evaluation of the Kennett/ McNamara Government's mandate. If a government implements policies it had promised not to implement or did not mention would be implemented, it may be said to have exceeded its mandate. Mitcham voters, at least, have declared that the government has exceeded its mandate, especially with regard to WorkCover and the Auditor-General.