Let’s imagine a scenario. You’re self-employed and have diligently paid your taxes for a number of years. There have been, in that time, several instances where you have sought tax advice from HMRC on what was and wasn’t acceptable to it. You have always followed the advice that you have been given and naturally, you have been as tax-efficient as possible and taken advantage of whatever tax breaks were on offer and accounting methods were practical.

Then, the government of the day decides that the system should be changed. It enacts a retrospective law meaning that tax breaks that you were advised to take previously no longer apply and the tax-efficient accounting methods you used are illegal. It passes legislation to say that those who used those tricks should be named and shamed in the national press and will be retrospectively charged for the benefit they derived.

Half the population is issued with letters from HMRC surcharging them for tax liable under methods that were cleared by tax authorities at the time. They are given a deadline to pay up and are photographed on their way to tax offices with chequebooks in hand. Half lose their jobs.

Now, I admit there are a few key differences between the above and MPs expenses. It’s taxpayers’ money, for one (although the ownership of money to me is a red herring). They won’t be much out of pocket and some of them, just a few, have probably committed criminal offences. But the principle is similar – here we have a group of people who operated under a code of understanding run by a responsible body – the Fees Office – and who have had retrospective justice foisted on them by a hawkish media.

Yes, the system was evidently over-generous and of a previous time. It needed – and still needs – serious reform and clarity for MPs and public alike. And I certainly don’t hold any candle for Jacqui Smith, one of the worst Home Secretarys this country has ever suffered.

But I don’t understand the fair play in saying to anyone that the rules have now changed and that they will be applied in such a way as to make it necessary for you to make a public apology for things that were at the time entirely within the system.

To those who say that MPs should have known that the system was rotten and not claimed for these more outlandish items I simply say – would you have done the same? Our DNA is impregnated with selfish behaviour that only the best will overcome and grabbing everything to which you are legally entitled is a desire not limited to MPs.

The Telegraph will no doubt invite us to revisit time and time again its one decent scoop of the last decade but if we are to build trust in the system once again, we need to know when it is time to act for the future rather than dwell on the past.