ONE positive outcome from the parliamentary expenses scandal - it is hard to think of many others - was an increased emphasis on the character of our elected leaders.

As the public collectively gasped and thrilled at the moats, mortgages, and duck islands they had been unwittingly funding, many also came to realise that loyalty to a party, or faith in its manifesto, was somewhat undermined if the people at the heart of the political endeavour were shady, dishonest or actually fraudulent.

At best, it left a sour taste in the mouth: "Let's not think too hard about the means, and just concentrate on the glorious ends." At worst, it undermined the whole political enterprise, constructed, as it ultimately is, on trust.

So it is that, six years on, we are more conscious of what kind of candidate we are voting for. Let's be clear here: we were never uninterested in this. Political personalities have always mattered. But, today, "I acted within the rules" is less likely than ever to calm the electorate. Whether you are a politician, a banker, or a journalist, the public want to know your moral case, not just the legal one.

This is good news - or at least it would be if the public had any real concept of sin. The good news bit is reasonably obvious. For all the endless discussion of structural deficit reduction or working-age benefits, politics is about people negotiating how best to live together. Laws, regulations, policies, speeches: all bear the fingerprints of those who deliver them. The nation would not suddenly see its problems solved if we had a parliament of saints, but it would certainly help.

And therein lies the link to sin. Because we don't have a parliament of saints, and we won't ever have a parliament of saints. Unless the public realises that, every exposure of a parliamentarian who has been less than wholly honourable is liable merely to exacerbate the public's already intense disaffection and indignation.

Probing the integrity and character of our leaders and officials is, thus, sensible and reasonable, but it will only be profitable if we realise that those characters will never be flawless.

So, my advice is: do enquire into the personality and honesty of your candidates, and allow it to inform your judgement on them.

But don't pass that judgement until you have made the same enquiry of yourself.

Nick Spencer is research director at Theos.