After years of discussion, Congress is approaching a vote next month on a new $2 billion tax break for so-called "small savers" -- people with interest income from savings accounts.

When lawmakers return from their August recess, the House will consider legislation that would exclude from taxation the first $100 an individual earns on savings accounts. For couples up to $200 could be excluded.

The Roposal, sponsored by Rep. Henson Moore (R-La., is being touted as a needed means of boosting investment and productivity. It also fits in with election-year rhetoric about "helping the small saver."

Mooore's proposal now has 192 co-sponsors, and several imitators in the Senate. The tax break, which would apply only to accounts in institutions, that make mortgage loans, will be offered as a substitute to a new housing bond bill.

However, the bill also has some critics -- among them the White House and the Federal Reserve Board -- who contend the tax break would only enlarge the budget deficit and would not necessarily increase savings or investment.

Paul A. Volcker, chairman of the Federal Reserve Board, this week criticized the idea as "gimmickry," warning the measure would mostly favor deposits in thrift institutions over other forms of saving, and would not guarantee more investment.

Moreover, tax experts point out that although the bill ostensibly is aimed at the so-called "small" investor, it actually would give a bigger break to higher-income taxpayers.A tax break of this kind is worth more in higher brackets.

There also are questions about how much incentive the break would provide. Under an average 6 percent interest rate, the proposed $200-a-couple exemption would exempt interest from up to $3,300 in savings, not much by today's standards.

For someone in the 50 percent tax bracket, it would bring the after-tax rate of return on such a $3,300 deposit to 6 percent -- double the 3 percent that is left now after taxes -- but that is still below other forms of investment.

"We've never thought it would do much to encourage more saving," said a Treasury official familiar with the plan.

"It's a political gimmick," another tax man says, "something to give voters the appearance of equity."

Nevertheless the proposal is being pushed vigorously by the savings and loan industry, which views it as a way to increase its edge over commercial banks and other financial institutions.

The industry has tried unsuccessfully to get the measure passed in previous tax bills, but analysts say it may have a better chance this time because the political climate is more favorable.

Moore's proposal would be offered as a substitute for the House Ways and Means Committee bill continuing the tax break now given housing bonds -- a controversial piece of legislation that neither liberals nor conservatives like.

If moore does not prevail in next month's floor action, sources say he may try to tack the measure onto the big tax-cut bill that most observers now expect Congress to pass in January. But it could be dropped in the shuffle.

Both Congress and the administration have been criticized in recent months for not doing enough to help the "small saver." Although the first $100 in stock dividends is tax-exempt, interest on savings deposits is taxed in full.

The lawmakers voted last year to cut taxes on capital gains -- profits from the sale of stocks or other assets -- a move that mostly benefits higher income investors. Proponents say Moore's bill would help the "little man" as well.