As lobbying against a proposed corporate minimum tax builds steam--along with a parallel drive to preserve corporate tax sales--key members of Congress and the administration are exploring significant cutbacks in the basic business tax cut enacted last year as a way to raise money.

"It's a three-headed monster, tax leasing, the minimum tax and ACRS" or accelerated cost recovery system--the core of the business tax reduction, a congressional aide noted, referring to the choices before Congress as it faces the probability of a self-imposed mandate to significantly raise taxes this year.

The corporate tax cuts are extremely inviting targets for members of Congress. Politically, a reduction of the benefits would function to offset the claim that the 1981 tax act gave excessive breaks to corporations and the wealthy.

From another vantage, the size of the corporate cuts in the 1981 bill--$18.7 billion in fiscal year 1983, rising to $54.7 billion in 1986--make them highly vulnerable to a Congress facing deficits exceeding $100 billion.

Business lobbyists, in turn, are struggling to deflect this congressional interest toward tax hikes that would not directly hurt their clients' interests, including a broad energy tax and a surtax on individuals.

The ability of business tax lobbyists to influence decisions, particularly in the Senate Finance Committee, has been demonstrated repeatedly during consideration of past tax bills. This muscle is currently being demonstrated in the growing congressional opposition to a new corporate minimum tax, and the apparent willingness of Treasury Secretary Donald T. Regan to consider major modification of the administration's minimum tax proposal.

A Treasury aide said, for example, that the administration remains committed to enactment of "some form of minimum tax," but he indicated that the burden on corporations may be significantly lessened. As opposed to raising revenues, the aide noted that the major reason behind the tax is to ameliorate the "perception problem," the image that the Reagan administration favors the wealthy.

An alliance of 19 mining, steel, shipping and railroad companies, known as the minimum tax coalition, has hired the lobbying firm of Gray and Co. to press its claim that the minimum tax as originally proposed by the administration would raise its members' taxes by 137 percent.

On another front, two separate corporate alliances of companies seeking to preserve the controversial provisions of the 1981 tax act, allowing businesses to buy and sell tax breaks through paper transactions called "leases," have won some sympathy on Capitol Hill, although the provisions are almost sure to be signficantly modified.

But, despite the wavering on the minimum tax and tax leasing, there are strong signals that Congress will move to take back some of the cornucopia of breaks passed last year. These signals are coming not only from liberal Democrats who traditionally have supported tax reform proposals, but also from sources in the Treasury and from many Republicans.

This possiblity became apparent at a recent Ways and Means Committee hearing where one of the leading proponents of the 1981 tax cut, Treasury Secretary Regan, suggested that the measure might have gone too far.

Regan, in an admission that surprised many of the members of the panel, acknowledged that the tax bill in some cases goes beyond elimination of all taxation of profits from new investments and actually provides a subsidy channeled through the tax system to corporations purchasing certain types of equipment.

"We may have to draw the line at expensing," Regan told the panel. Expensing means that the taxes on profits from a new investment effectively have been reduced to zero. Treasury sources said they are considering a wide range of alternatives, many of which are also likely to be proposed by Sen. Robert Dole (R-Kan.), chairman of the Finance Committee, and by Democratic leaders on the Ways and Means Committee.

One of the most vulnerable parts of the 1981 tax cuts are business tax breaks that sharply accelerate the depreciation benefits in 1985 and 1986. Elimination of those provisions would do nothing to lessen the deficit problems in 1983 and 1984, but later on the savings become very large, raising from $1.7 billion in 1985 to $10.9 billion in 1986 and $18.9 billion in 1987.

Another method of restricting the benefits of the business tax break would be to limit the percentage of the cost of a piece of equipment that can be depreciated under the new, favorable schedules.

Current law allows a company to get an immediate 10 percent investment tax credit, and then to depreciate the full cost of the purchase, even though the credit covered 10 percent of the cost.

A proposal under review by both the Ways and Means Committee staff and by Dole, who said he plans to sponsor it as part of a tax package, would be to limit depreciation to the 90 percent of the purchase cost that is not covered by the investment tax credit.

This would raise $700 million in 1983, $2.4 billion in 1984, and $10.3 billion by 1987.

An alternative to this would be to lower the value of the investment tax credit. Reducing it from 10 percent to 7 percent would raise $3.4 billion in 1983, $7.6 billion in 1984 and $11.5 billion by 1987.