FOR those who saw it, it was unforgettable.

For those who didn't, it is best avoided.

Last week's STV debate between Deputy First Minister Nicola Sturgeon and Scottish Labour leader Johann Lamont was abysmal.

Although the adversarial format was partly to blame, the sight of two of Scotland's most senior politicians continually shouting over one another to produce a meaningless din was a new low for the independence referendum.

While Yes and No diehards may have cheered their respective ­champion, undecided voters tuning in for information and enlightenment must have been appalled at what was on offer.

There was no attempt to debate, only needle, plus noise and efforts to drown out the opposing view.

Both sides quickly realised it was not their finest hour, but by then the damage was done.

There are now 200 days until we cast the most important vote of our lifetime. This weekend, politicians from all parties are using the milestone to urge people to consider what a Yes or No would mean to them, their families and their country.

But instead of asking us to reflect, it is the politicians who should look at themselves and ask what they need to do to improve the basis for that historic decision.

Right now, they are applying abrasive election campaign tactics to an event that demands to be treated far more sensitively and cannily.

The large number of undecided voters points to a hunger for clear information that is not being met by endless claim and counter-claim.

By refusing to pre-negotiate elements of an independence settlement, a tactic designed to keep as many question marks in the air as possible, Westminster is partly culpable.

But so is the SNP when it flatly refuses to accept almost everything the unionist parties say.

The SNP may be right that rejecting a formal currency union would be perverse for the rest of the UK, but if the rest of the UK accepts the consequences it is not impossible. It is simplistic to discount it as pure bluff.

This is undoubtedly a hard cycle to break.

September 18 is a binary choice between Yes and No, passions are already high, and the tribal divide between the opposing sides runs deep.

Both those campaigning in the referendum must aim to win the peace as well as the war.

They must beware sowing a bitter legacy.

In less than a fortnight, the parties start to hold their spring conferences.

It is a chance for a different approach. For the side that stops treating the referendum as another election scrap, that stops the knee-jerk denials and instant attacks - that starts, in other words, to exhibit maturity and balance - the rewards could be great.