It would be impossible to implement the legal enforceability of election promises though, because of the format and procedures of our governmental’ and legal systems. The major reason is that the question, in stating “legally accountable,” suggests that election promises should be enforceable before the courts. However, that would mean that judges would be overseeing the operation of Government and the Parliament. If this was the case, it “would be contrary to Dicey’s Rule of Law” (Senator O’Chee, 1996), which requires laws to be made by Parliament and interpreted by the courts; therefore keeping the legislative, executive and judicial powers separate. If the courts were able to enforce election promises, they would have to possess the right to force the Parliament to legislate in certain ways, or to review legislation to ensure that it conforms with prior promises.

As has been made evident, it would be impossible to make politicians legally accountable for their election promises, due to the fact that the separation of powers and Dicey’s first rule of law forbid it.

In addition to these, on numerous occasions there have been calls for politicians to be covered by the Trade Practices Act 1979. This, and supplementary State Fair Trading Act legislation, stipulate that parties shall not in trade or commerce engage in misleading or deceptive conduct, or conduct that is likely to mislead or deceive. Many people have questioned whether Trade Practices legislation would bind politicians to honour their election promises. The answer is, regretfully for many, “No.” The reason is because politicians are not involved in “trade or commerce,” as illustrated in the Durant v Greiner (1990) case.

Norris, Brendan. 1997. Should Politicians Be Legally Accountable for Their Election Promises? Interstate - Journal of International Affairs 1996/1997 (2), http://www.inquiriesjournal.com/a?id=1160

While these considerations probably affect candidates' decision-making to some degree, this Note begins with the proposition that the present nonlegal mechanisms are insufficient safeguards.

This Note does not argue that campaign speech should always be held to the same standards of accuracy to which other forms of speech are held. Campaign speech is unique in form, with its own idioms and rhetorical devices, and serves unique purposes. Often, when a candidate promises, he simply urges his "vision" or general policy preferences, akin to the legitimate business practice of "puffing."' For instance, a candidate's promise not to raise taxes might be understood to rhetorically convey the message: "I am less likely to raise taxes than is my opponent."

Political lies, so often assumed to be trivial by those who tell them, rarely are.... When political representatives or entire governments arrogate to themselves the right to lie, they take power from the public that would not have been given up voluntarily. Large extent shared with the entire class of politicians - the public concludes not only that the particular individual lacks credibility but also that politicians in general are not to be trusted. This makes 'loss of credibility' a public evil, the converse of a public good, and as such it is overproduced for precisely the same reasons public goods are underproduced. Therefore, the common stigma attached to lying, acting as a disincentive in nonpolitical contexts, is lessened in the political context.
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Today, that threat is demonstrably minimal; for example, in 1990, for the fourth straight election, over ninety-five percent of the congressional incumbents who ran won reelection despite wide- spread voter discontent. Whatever the reasons for this high incumbency rate - many undoubtedly having little or no relation to campaign lies - elected officials enjoy a high level of job security.
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None of these decisions, however, offers a reasoned explanation for this judicial inability or unwillingness to hold candidates to their words.

Deciding the case on other grounds, the court stated that "[t]he breach of such promises is to be reckoned with at the ballot box and not in the courts of this state."77 Similarly, in City of Farmers Branch v. Hawnco, Inc.,78 plaintiffs tried to enjoin a Texas city from considering changes to a zoning ordinance because certain officials had campaigned on a platform against such changes.

Sencer, Stephen D.. “Read My Lips: Examining the Legal Implications of Knowingly False Campaign Promises.” Michigan Law Review 90 (1991): 428-469.