As chairman of the House Republican Conference, I take exception to the conclusion of The Post's lead editorial June 21 on the future of Social Security.

First, let the numbers speak for themselves. The Congressional Budget Office (CBO) estimates that the non-Social Security surplus will grow from $14 billion in the fiscal year that begins in three months (FY 2000) to $129 billion six years later (FY 2006). Even by Washington standards, that is not a small amount of money.

Second, we do not need to raise or evade the budget caps to pass this year's appropriations bills. If we save one penny of every dollar spent on current government programs, the appropriators can meet their savings goals.

Finally, the increase in revenues from a capital gains tax rate reduction is by no means artificial. This reduction is an incentive to investors to shift their money into more productive and efficient investments. That results in job and productivity growth and increased tax revenues.

The Social Security lock box is real as long as we remain committed to it. It may be hard for the establishment to accept it, but we Republicans are committed to locking away the Social Security trust fund to guarantee the retirement security of hard-working Americans.

J. C. WATTS JR.

U.S. Representative (R-Okla.)

Washington