Leading article: The dam has burst – and the waters of reform must flow

MPs' expenses and the drive for constitutional change are related

Until this week, talk of a new mood of political "engagement" sparked by the MPs' expenses scandal seemed a bit optimistic. People were certainly keen to gripe about the venality of their local MP, perhaps even sign a petition to unseat them. But the mood was more rejection than engagement.

This week, however, a ray of sunshine has penetrated the negative gloom. The upsurge in public enthusiasm for reform of our democratic system is an encouraging sign that some good might yet emerge from this destructive scandal. People are no longer exclusively discussing the malfeasance of MPs. They are now also talking about how our politics can be made healthier, more truly democratic. And if the response from readers of this newspaper to our Campaign for Democracy is any guide, the public regards the two issues as connected.

Some maintain that this talk of reform has been cooked up by the political classes to distract attention from the toxic embarrassment of the expenses revelations. There might well be an element of this in certain corners of Westminster. But it is too cynical to dismiss the motives of all those politicians advocating reform in this way. The Liberal Democrats, in particular, have a strong record of advocating such changes. And the Health Secretary, Alan Johnson, who kicked off this latest push to reform by proposing a fresh look at the proposals of the 1998 Jenkins commission, has also been a consistent supporter of a new voting system.

A more credible objection to the attempts by the party leaders to hitch democratic reform to the bucking horse of expenses is that the sort of measures being proposed – a more proportional voting system, a more independent role for the House of Commons, greater responsibilities for local government – would be no guarantee of good behaviour from MPs.

In a narrow sense this is true. It would be silly to suggest that the first-past-the-post system was responsible for MPs shamelessly padding out their expenses claims. Furthermore, countries that have more proportional voting systems still suffer from corruption. And democracies with stronger and more independent legislatures than Westminster have experienced their share of graft scandals. Yet there remains a case for linking the democratic deficit with expenses abuse. The sheer strength of the public reaction to recent revelations of MPs' behaviour – in some cases out of all proportion to the scale of the misdemeanours committed – indicates a profound disconnect between MPs and their constituents; a fundamental breakdown of trust between politicians and the general public.

Of course, no voter is ever going to be sanguine when confronted with evidence of greed on the part of his or her political representative, but the amount of vitriol provoked by this scandal indicates something more profound has gone awry. It is as if a dam has burst and decades of frustrations over the iniquities of a loaded voting system, a supine Commons and unresponsive local councils have come flooding out at once.

To be clear, this is not about letting MPs off the hook. Those parliamentarians who have fraudulently claimed expenses should face dismissal and possibly criminal prosecution. And a general election is needed soon to drain the poison created by this scandal. But it is becoming increasingly clear that such action alone will not restore public trust in our political system. For that to happen, a thorough overhaul of the unsatisfactory electoral and political status quo is required.