While George Will's comments about Budget Committee Chairman Bill Gray's qualifications to be on the Democratic presidential ticket were merited {op-ed, July 26}, his portrayal of what he referred to as Rep. Gray's "piggy bank," the so-called deficit reduction trust fund, was inaccurate. According to this plan, new revenue -- $19.3 billion in unspecified tax increases -- would be used only to reduce the deficit beyond cuts in federal spending that are to be made by Congress.

This plan is a bookkeeping gimmick that would make Houdini proud. Decisions about how much the government should spend are not made independently of decisions about how much revenue the government should raise, as the trust fund proposal would imply. Is the government really spending less than it would have otherwise because of the trust fund? No, if you consider that the FY 1988 budget resolution increases discretionary spending by $10 billion over this year's spending. The budget resolution counts on the $19.3 billion "piggy bank" trust fund to offset this increase.

This year's budget, like all recent budgets, seeks to reduce the deficit by constraining the rate of spending growth below the rate of growth in revenues, not by actually cutting spending. Specific program cuts reflect shifting priorities, but the bottom line is growth, and the "piggy bank" of taxes is essential to fund this growth and very modestly reduce the deficit.

The key to understanding the trust fund proposal is that the amount of revenue and spending remains the same whether or not the new tax money flows through a special account. The government's net deficit is the same with or without this accounting trick. And so is the amount that must be borrowed to finance it.

If Chairman Gray and his Democratic colleagues are looking for meaningful ways to reform the budget process, I urge them to consider the reform proposed by the Republican task force on budget reform, on which I serve. The measures we have proposed are real reforms that would dramatically increase policy-makers' accountability to the taxpayers.

My appreciation for Rep. Gray's talent is sincere, but I am disappointed that the Democrats have resorted to using a gimmick like the trust fund when there is serious work to be done. NANCY L. JOHNSON U.S. Representative (R-Conn.) Washington