Senate Republicans' $792 billion tax cut plan came under fire from both sides yesterday, as moderates and conservatives began pushing alternative proposals for how to distribute expected budget surpluses over the next decade.

Now that the House has narrowly approved its own tax-cutting plan, the debate over taxes has shifted to the Senate, which plans to start floor debate Wednesday. The Senate Finance Committee has approved a bill lowering the rate of the bottom tax bracket by 1 percentage point, providing relief for married couples, and offering incentives for retirement savings and breaks for big business.

But as in the House, many Senate moderates believe the tax cut is too big, while conservatives believe it does not go far enough in providing broad-based income tax relief.

Four Finance Committee members -- Sens. John H. Chafee (R-R.I.), John Breaux (D-La.), Bob Kerrey (D-Neb.) and James M. Jeffords (R-Vt.) -- plan to offer a roughly $500 billion tax cut measure when the Senate begins voting this week.

Chafee spokesman Nicholas Graham said his boss was trying to avoid the kind of "massive partisan gridlock" which just occurred in the Senate over managed care reform. Graham said the senators question the economic assumptions underlying the surplus projections.

Conservative GOP Sens. John D. Ashcroft (Mo.), Rod Grams (Minn.) and Kay Bailey Hutchison (Tex.), by contrast, announced yesterday they would support a $792 billion tax cut bill that would reduce taxes across the board by 10 percent -- a plan comparable to parts of the just-passed House bill.

Grams said such an approach "is a responsible path -- a much more responsible course than leaving those dollars in the hands of the president or congressional Democrats, where it would be spent expanding the size, scope and cost of the federal government."