TWO salient matters form the background to yesterday judgments. The first of these is the McKenna case - which the court had ruled that the Government's expenditure on advertising, on one side only of the referendum campaign, amounted - as was said yesterday - to a "constitutional wrong". Secondly, though the Supreme Court chose not to make much of this, the slimness of the majority in the referendum might also have been thought relevant.

The Supreme Court ruled that the net question, as lawyers like to say, in the Hanafln case came down to a question of cause and effect, namely whether the constitutional wrong had been responsible for the Yes side's victory. This ruling is not beyond controversy. It is not always followed elsewhere in the law. As an example, take the case of an administrative tribunal of four members, one of whom is biased against a party before the tribunal. If this party complains to the High Court that the tribunal decision was flawed by virtue of the bias, his claim is likely to succeed, seven if it is the case that he had lost before the tribunal by (say) four to nil. The point is that the court reviewing the tribunal's decision is, for various policy reasons to do with public confidence in tribunals, most unlikely to rule that no harm has been done.

IN the Hanafin case, once the decision was taken to approach the issue on the basis that Mr Hanafin had to prove the defeat was caused by the unconstitutional action, then he plainly faced an uphill battle. For, as Mr Justice O'Flaherty said: "There was no evidence to prove that the advertising either did or did not affect the result".

Given the absence of evidence either way, how did the court unanimously come down against Mr Hanafin? There are various lines of argument.

One was the simple precept, which applies generally in the law, that the onus rests upon the plaintiff to prove the facts upon which he relies. It is true that in certain areas of the law, where establishing a fact poses peculiar difficulties, a special legal technique has been developed to assist the disadvantaged party. This consists of a presumption in his favour so that the onus of proof is shifted to the other party. The court was not inclined to import this special technique into the present novel area.

Mr Justice Barrington remarked that no voter had come forward to say he had been misled by the Government advertising campaign, it would, however, have been inherently difficult, especially in view of the secrecy of the ballot, to have found 4,000 plus (the necessary number) voters, or even a smaller number, to say that they had voted Yes because of the advertising, but would have voted No without it.

The second argument did adopt a presumption, but one which told in fa of upholding the referendum. This is the presumption of constitutionality, which is said to rest on "the respect which one great organ of state owes to another". It means that a law or official act will be taken to be constitutional unless the contrary is clearly established. This precept has been used in various other areas of constitutional law, but it seems strange to press it into service to protect an action (the referendum) which is part of a transaction which had already been stamped as unconstitutional as McKenna.

Another hue of argument was that - as was said by the Chief Justice quoting a North Dakota case - the sovereign people are presumed to know what they want. This is a fundamental principle of law, which is built upon the sound policy that if it were open to a court to start queuing: different voters' varying levels of comprehension, information, motivation, and so on there would be no knowing where the thing would stop. This is sensible but, unfortunately, essentially difficult to reconcile with the spirit of McKenna.

This legal principle was supported by a point of fact, namely that it happened that McKenna was widely reported so that all voters knew about it and were aware of the unconstitutional nature of the advertising toe which they had been subjected. Does it follow from this that the voters could therefore erase the effects of the advertising from their minds?

Some members of the Supreme Court were happy to make this assumption.

One ought to note, finally, an omission. There was no reference to what US courts call the political question.

This is an issue which has so high a political content that it is inappropriate territory for a court, whose involvement is therefore likely to be improper by the public.

This doctrine of judicial abstention has solid support in all Irish cases on referendum campaigns until McKenna, which abruptly reversed this train of precedents. In Hanafin, it was too late to revive explicitly this notion, yet its ghost hangs heavily over the judgement.

In short, the Hanafin judgments are legally unconvincing because while paying formal homage to McKenna, they are really in line with the divergent pre Hanafin precedents. Does this inconsistency and uncertainty matter? Yes; because of the importance of certainty in law, especially in areas of political controversy.

WHAT lessons does this saga teach? In the first place it seems clear from McKenna that in any future referendum, the government will have to provide equal amounts of finance for each side of the campaign.

Incidentally, one might note that this point has been taken up and offered as a reason for withdrawing and modifying the Electoral Bill because it would give public funds only to those parties already represented in the Dill. Thus, it is said, it violates the McKenna principles. Dr Michael Forde SC, counsel for Ms McKenna, however, has publicly doubted whether McKenna really goes this far and I agree with him. It could be that this was just an excuse for withdrawing a Bill which was thought to be unpopular with the public.

In the light of the result Hanafin the following query might be raised.

Despite the violation of the Constitution in the divorce campaign and the paper thin majority at the poll, no harm came to the referendum result. Does it follow from this that, in a future referendum campaign, the government need not give equal financing to each side? A part of the answer to this is that someone would probably take a case at an early stage, to halt the government funded advertising campaign. But even if this did not happen if, after the result was announced, there was a Hanafin style challenge in the courts, Hanafln itself might well be distinguished. The point of distinction would be that, this time around, the government had a warning that such conduct would be unconstitutional.

There was a flavour of this point in Mr Justice Barrington's judgment in Hanafln. It was in a passage in which he was facing up to the implicit question: if Mr Hanafin loses, what exactly was the cash value of McKenna? His response - the only one available - was that, in November the government had terminated its advertising campaign, as soon as it heard of the McKenna decision.