Whether any of the proposed changes are put into legislation remains to be seen. History suggests the most likely result will be a long period of fitful discussion, while public outrage gradually cools and moves on to other targets. In the end, the proposals will probably be quietly pigeon-holed, ready to be brought out again in response to the next bout of deplorable behaviour by individual parliamentarians.

On the other hand, this crisis may be different from its predecessors. The stakes have been raised significantly by the government's minority status and precarious parliamentary position. In normal times, a government with a secure majority would have cut Thomson loose much sooner and more decisively, and would have had no truck with such a dubious opponent as Slipper. The present Labor government, however, needs these two MPs' support, however morally questionable, and must continue to share in the consequent opprobrium whipped up by the opposition. The issue of political morality will remain salient, at least until the next election.

At the same time, the crossbenchers, on whom the Gillard government also crucially depends, have made parliamentary reform, including legislating for parliamentary ethics, one of their key demands. They will continue to press hard for a legislative response during the rest of Gillard's term of office.

Would new ethical institutions and procedures significantly improve parliamentary standards? Or are they, as the critics argue, an expensive waste of resources and a diversion from other, more effective instruments of improvement?

One complicating factor is that supporters of codified ethical standards and integrity commissions are not all seeking the same outcome, a point overlooked in much media commentary. The most common proposal is for a code of conduct solely for parliamentarians, usually (but not always) coupled with a commissioner to oversees its application. This is the focus of the two committee inquiries and of the Prime Minister's agreement with the independents. However, another group of advocates, led by the Greens, have been hoping to establish an anti-corruption watchdog that would oversee the entire federal government, both Parliament and the public service. The models here are the NSW Independent Commission against Corruption or the Queensland Crime and Misconduct Commission.

In 2010, then Greens leader Bob Brown introduced a bill in the Senate to establish a national integrity commission with a wide range of proposed functions, including the investigation and prevention of misconduct and corruption in all Commonwealth departments, agencies and among federal parliamentarians and their staff, as well as in the Australian Federal Police and the Australian Crimes Commission. The integrity commission would also offer independent advice to ministers and parliamentarians on conduct, ethics and matters of propriety. Brown's bill still languishes before the Senate, so far without attracting sufficient major-party support.

However, the Greens, along with independent senator Nick Xenophon, have used the present Slipper-Thomson crisis to try to rally support for a federal anti-corruption body that would cover members of Parliament without being confined to them. Greens MP Adam Bandt recently gave notice of a bill in the House to establish a national integrity commissioner.

The Greens are not openly opposed to a parliamentary code of conduct. But they see it as of minor value compared with a more wide-ranging commission that would investigate corruption in all areas of the Commonwealth. Indeed, if the precedents of NSW and Queensland's anti-corruption commissions were followed, the work of such a body would be much more concerned with corruption in government departments and agencies than with standards of parliamentary behaviour.

The case for a federal, government-wide integrity commission is arguably stronger than that for an exclusively parliament-focused code and commission. Compared with MPs, public servants are subject to much less constant scrutiny. Many are also responsible for major disbursements of public funds, offer many opportunities for various forms of corruption. Admittedly, corruption scandals have been comparatively rare in the APS compared with state and local levels of government. Institutional watchdogs, such as the Finance Department and the auditor-general, provide a valuable check on agency spending. In all likelihood, the proposal for a Commonwealth anti-corruption agency will continue to lie dormant until a large corruption scandal emerges involving federal public servants.

In the meantime, attention is firmly focused on MPs and their ethical standards. The discussion paper issued by the House standing committee of privileges and members interests, in November 2011, gives a good summary of the key issues. To begin with, it discusses the pros and cons of codes of conduct themselves and whether they should be brief statements of general principle or more detailed prescriptive rules. The international consensus among experts in organisational ethics supports a values-based rather than a rules-based approach for all codes of professional ethics.

Among parliamentary codes, the most influential model in the Westminster world is the British code adopted in the mid-1990s after the ''cash-for-questions'' scandal. It contains seven aspirational values, the so-called Nolan principles, named after Lord Patrick Nolan who chaired the original House of Commons committee for standards in public life. These principles are selflessness, integrity, objectivity, accountability, openness, honesty and leadership. The British code also provides for rules of conduct and declarations of interests.

The next major issue is how the code is to be enforced and the role, if any, of a designated integrity commissioner. The discussion paper canvasses three general approaches: no commissioner, i.e. a system of self-regulation, essentially through the privileges committees of each chamber; a commissioner operating in a purely advisory role; and a commissioner with power to receive and investigate complaints, as in Britain.

The British parliamentary standards commissioner oversees the register of members' interests, advises MPs on ethical matters, and investigates complaints about members, which may be referred to the committee on standards and privileges. Canada adopted a similar system in 2004 and the House of Representative committee's discussion paper clearly sees the British model as the way of the future. This model is also reflected in the specific commitments on parliamentary reform that form part of the formal agreements between the prime minister and the independent MPs, and which the discussion paper reprints as an appendix.

The effectiveness of such ethics regimes remains a matter of dispute. They certainly generate a certain amount of procedural activity. The latest annual report from Britain's parliamentary commissioner for standards records the receipt of more than 100 complaints, of which 33 were investigated and 15 were the subject of memoranda to the committee on standards and privileges. The complaints covered a range of different issues, including members' postage and printing allowances, travel entitlements, and entries in the register of members interests.

On the other hand, sceptics point to Britain's parliamentary expenses scandal in 2009, which revealed widespread abuse of accommodation allowances and expenses and caused a crisis of public confidence in Parliament. After more than a decade in operation, the code of conduct appeared to have done little to raise ethical standards among British parliamentarians. The heady aspirations of the Nolan principles seemed as distant as ever.

In Australia, introducing a code of conduct and integrity commissioner may help to raise compliance standards on matters of financial entitlements and in the declaration of members' interests. At present, members' financial entitlements are administered by the Finance Department, which has tightened its controls in recent years, partly through prompting from the Auditor-General and partly through the reforming zeal of the previous minister, Lindsay Tanner. The department now publishes six-monthly reports, listing expenditure by each MP on travel and office expenses, which have a powerful naming-and-shaming effect. However, a commissioner with investigative powers could bring another useful level of scrutiny.

Whether the proposed changes would do much to raise parliament's general moral standing is more questionable. Public distaste for politicians centres on the dishonesty and superficiality of political discourse and the incivility of adversarial two-party politics, deep-seated aspects of our political culture. Such contempt has recently been heightened by the compromises of minority government which collide with public expectations that governments will stay true to their election mandates. No code of conduct or integrity commissioner will make much impact on these broader issues of public trust.

Nonetheless, the independent MPs are clearly intent on using their leverage to pass the necessary legislation during the current Parliament. Even if they fail, the major parties might be unable to maintain their indifference for much longer. Internationally, codes of conduct and parliamentary commissioners are becoming standard features of all mature parliamentary systems. At some point, a government will find it easier to fall into line, however unenthusiastically, rather than bear the odium of standing out against the tide of international best practice.

Richard Mulgan is an emeritus professor with the Crawford School of Public Policy at the Australian National University.

richard.mulgan@anu.edu.au