Business Opinion: Let us try to put this into perspective, once and for all. A year ago, pre-Budget speculators were sure that the rules governing the Special Savings Incentive Scheme (SSIS) would be changed.

They were so convinced that most commentators, and others, implored readers/ listeners to up their investments. Otherwise they would lose out. Some people agreed and topped up.

These advocates were wrong - the scheme was not restricted, or abandoned - but they were right to extol the virtues of a very generous savings scheme.

A repeat scenario was rearing its head last month. This was scotched by Bertie Ahern and, yet again, by Charlie McCreevy. And next year during the kite-flying season, pressure for changes is likely to erupt yet again.

Contrary to many views, changes cannot be made like a flick of a switch. Indeed, any tinkering with existing schemes would be fraught with legal difficulties that would likely cost the State dearly, and firmly place it in the not-to-be-trusted category.

Just look at the details enshrined in the Finance Act 2001. Often an Act will provide a framework for a scheme and leave it up to the regulations to be specific.

Readers of Acts will know the usual caveat all too well. It adds a rider that gives the minister an out.

That out will give precise details but then add words like "or such as may be determined by the minister".

That provides enormous power to the relevant minister. In effect, it gives him/her carte blanche to make changes as he/ she feels fit, at a later stage, merely by making a ministerial order.

That is not the case with the SSIS. Now any alterations to the main terms (sections 33, 848D and 848M) to the Finance Act 2001 (an Exchequer contribution of 25p, in the form of a tax credit, for every £1 saved, and an exit tax of 23 per cent on the investment return, according to the initial terms), in schemes already in place, would need amending legislation.

That would have to be approved by the Dáil. But such a move could be successfully challenged by the investors under the legal doctrine of legitimate expectation, following that extensive inducement campaign.

Technically, it would be difficult retrospectively to change the exit tax because this is locked into the 2001 income tax code. Existing schemes are safe.

But what about going forward? The annual percentage gains, to the saver, from the Exchequer are, of course, far greater in the latter years; in the last year (the fifth for the saver) these will be up to 25 per cent. Those contemplating topping up (if everyone went this route it would cost the Exchequer a whopping extra €360 million!) might not have as strong a case under the guise of legitimate expectation.

But who is to say that this was not their expectation from the start? It could be argued that if investors were given a window of opportunity - say two months - to top up before banning top-ups that any claims under legitimate expectation could be diluted considerably.

But importantly, redemptions will take place between May 2006 and May 2007, conveniently slotted right in the middle of the next general election time. Was this plotted all along?

Is this administration going to foul up the feel-good factor associated with a return of these funds, particularly from the deposit accounts? Hardly.

On the other side of the coin, the Exchequer returns should be taking on a much more acceptable hue. With the tapering off of the expensive tax credits, the tax returns will look much healthier; that element, of course, would be influenced by the amount of top-ups, if any.

These credits have cost the Exchequer €760 million in the first two years to May 2003. The SSIS is, in effect, a six-year scheme from the Exchequer's perspective as investors had 12 months to jump on board.

It has been a relatively slow burner. In the first eight months to December 2001, €356.6 million was invested by savers at a cost of €89.8 million to the Exchequer.

In 2002, savers put in €1.86 billion, which cost the Exchequer €459.6 million.

In an answer to a Dáil question in May, Charlie McCreevy estimated that the cost to the State this year would be €530 million, based on figures for the first four months.

The penalties applicable to those who breach the rules of the scheme do not appear to have had any impact on the savings pattern. The 1.14 million investors, representing around 40 per cent of the eligible population, who signed up to the scheme undertook to subscribe to the account from funds from their own resources "without recourse to borrowings, or the deferral of repayment (whether in respect of capital or interest) of sums already borrowed".

Those in breach of the declarations are guilty of an offence and liable, on conviction, to a fine of €1,900, or, at the discretion of the court, imprisonment of up to six months, or both.

There now seems to be a discernable pattern to SSIS savings and the payments from the Exchequer. They built up slowly from May 2001, when savings amounted to €7.8 million (Exchequer payment €2 million) to €85.8 million (€21.3 million) in February 2002.

But then with the deadline emerging, savings shot up to €102.1 million in March 2002 and to €173.5 million in the following month. Savings appeared to have peaked at €184.3 million in January 2003 and have now settled down to €181.5 million per month with a monthly cost of €45 million to the Exchequer.

These should stabilise over the immediate future. The average monthly subscription as at December 31st, 2002, amounted to €158 - which proves that users of the scheme are not all high rollers as claimed by some politicians - according to the Revenue Commissioners.

It is likely to be only marginally higher this year but that will still be well below the allowed maximum of €254.

As the last few years of the scheme approach, there will be a very strong incentive for investors who can afford to to top up to the maximum, which may well bring further pressure to dilute the scheme.

If everyone increased their contributions to the maximum, it would cost the Exchequer a whopping extra €360 million.