Why The Court Of Public Opinion Is A Bad Thing

In the heat of the discussion over the pension of Sir Fred Goodwin, Harriet Harman let slip this phrase:

"It might be enforceable in a court of law this contract, but it's not enforceable in the court of public opinion and that's where the government steps in."

It seems to me that this is a very worrying thing to say.
If Sir Fred's contract is formally valid, then presumably the only way that the Government could stop the pension is by an Act of Parliament. Parliament has the authority to do this; Dicey once famously said that the only thing Parliament could not do was bind its successors. The doctrine of Parliamentary Sovereignty is not under discussion here, indeed I would argue that Parliament has never been sovereign. But if Parliament were to do this, the legislation would probably have to be retrospective, that is, to outlaw something that has already happened. It has happened before, for example in the War Damage Act 1965.

But it is a dangerous path. If Parliament makes something illegal tomorrow retrospectively when it was committed today, then we live in uncertainty as to what is culpable conduct today. In short, the law becomes a mess, allowing Government to act arbitrarily, for example by passing a law saying anyone who went to a football match yesterday is guilty of an offence. Also, people need to know what the law is today so that they can make a conscious decision to act within or without the law. Retrospective action denies the autonomy of the individual to decide to act in a lawful or unlawful manner at the time. The principle of non-retrospectivity is therefore too important to tinker with even in isolated cases.

This is where the "court of public opinion" comes in. The justification that Labour are claiming for such grossly unconstitutional action is that the public demands, so the government must act. So the Government feel required to act contrary to established principles of good law for the sake of public approval. Such an idea is dangerous and should not take root in government. We have ideas as to what makes good law for a reason, and it is precisely so that a government cannot act arbitrarily or retrospectively on a whim.

Please can we hear no more of this court of public opinion? It's not worth sacrificing our Constitutional principles for the sake of approval ratings.