There is a worrisome disarray at the top of the Reagan administration, which, in the face of deepening recession and soaring budget deficits, hasn't been able to get its economic act together.

With the deficit for fiscal 1984 expected to exceed $200 billion, the president is being pressured by some aides to reduce planned increases in defense spending, by others to raise taxes, and by still others to let the burden of deficit-shaving rest on the welfare side of the budget.

The reality is that some combination of all these measures will be needed, if not in fiscal 1984, later on. But the last thing President Reagan wants to talk about now is another tax increase. He made that clear in an unprecedented public rebuke to Treasury Secretary Donald Regan, who had leaked his own preference for a new tax hike.

All Reagan's advisers agree, in principle, that the budget to be presented next month by the president must set out a scenario for reducing deficits over the next four or five fiscal years in a way that financial markets will accept as credible.

That means a descending pattern of deficits, lower for fiscal 1985 than 1984, and so on--in absolute dollars and as a percentage of GNP. "We can't do it with mirrors," says an official.

The deficit numbers projected for the out-years--fiscal 1985 through 1988--"are frightening," says one who has seen them. Unless reduced by both spending reductions and tax increases, the deficits soon top $250 billion and could run over $300 billion for fiscal 1988.

This is the result of the original, badly conceived Reaganomics program. It risked putting in place huge tax cuts, along with big defense increases--and never achieved the economic expansion necessary to avert this sea of red ink. There is, instead, a recession that could turn into depression.

Reagan's dilemma has no readily apparent solution. What's worse, no one stands out as a leader among his economic advisers. As they will admit privately, there is little coordination of their views when they speak out in public. "I'm surprised that the disagreements (on policy) are voiced so openly," says one official.

Theoretically, domestic economic policy is worked out at an informal "Tuesday breakfast" session hosted by Secretary Regan. The team-- no alternates allowed--includes Secretary of State George Shultz, OMB Director David A. Stockman, Economic Council Chairman Martin Feldstein, Commerce Secretary Malcolm Baldrige and White House aide Edwin Harper.

As part of a package, they have discussed higher taxes at some stage of the game. It is clear, says one participant, that if Ronald Reagan believes one thing as if it were written in the Scriptures, it is this: you don't get out of a recession by raising taxes.

So all hell broke loose when Secretary Regan leaked the idea of a tax increase, presumably to begin in fiscal 1984. Says a colleague: "Don is just unpredictable." Regan, it will be recalled, only a few weeks ago floated the idea of advancing the July installment of the Kemp-Roth tax cut to the beginning of the year.

Regan also did a U-turn on the need to bolster the resources of the IMF as soon as the depth of the Third World debt crisis and the involvement of the American banks became clear. In this situation, Regan began to pay more attention to what Fed Chairman Paul Volcker was telling him about the desperate shape of the global economy, and less to the monetarist concerns of Treasury Undersecretary Beryl Sprinkel.

Stockman is still in the shadow resulting from his indiscreet disclosure late in 1981 of his honest doubts about the original Reaganomics program, and has little influence in shaping macro policy. He is using whatever clout he has, along with Feldstein and Baldrige, to press for spending cutbacks across the board, including a slice in the projected real increase in the Pentagon's budget.

Economist Feldstein, the newest boy on the block, has played an important role by insisting on realistic economic predictions--no more "rosy scenarios." He is respected at the White House, but his relationship with Reagan is still developing.

What Reagan desperately needs is a new policy package that at least holds out a reasonable hope for reducing the later-year deficits. But beyond that, he needs a take-charge guy for economics, someone who operates like George Shultz did in the Nixon administration. The danger is that Reagan will soon appear to be as indecisive as Carter. If the financial markets see no real relief on budget deficits in the later years, we could be in the double-digit interest-rate soup once again.