Top House Democrats and the Bush administration may be far apart on taxes and budgets, but there is one "revenue enhancer" that they both like.

This week -- perhaps as early as today -- they will gang up to try to push through the House something called a "passenger facility charge," which could add as much as $12 to a round-trip air fare inside the United States.

The charge, which some critics have been impolite enough to describe as a "head tax," could be levied by some 71 major airports to pay for local improvements and expansion. An air traveler could pay the fee twice on a one-way trip, once at his departure point and a second time if he or she stopped at another airport en route to connect to a final destination.

The fee will hit the pocketbooks of millions of passengers -- and of the inveterate air travelers who make up the House. But in this case, politics and parochial interests have given the legislation a powerful head of steam.

The fee provisions are embedded in legislation that was reported out of the Public Works Committee July 10. It reauthorizes spending on airport improvements, Federal Aviation Administration programs, and safety through September 1992, and was crafted in lengthy negotiations that involved the administration, airport groups, Rep. James L. Oberstar (D-Minn.) of the aviation subcommittee of the Public Works Committee, and Rep. William Lehman (D-Fla.), chairman of the transportation appropriations subcommittee.

The passenger fee has emerged as the centerpiece of the package. It is being pushed hard by Transportation Secretary Samuel K. Skinner, whose strategy is to beef up spending for airports without worsening the budget deficit.

Skinner has found support from such Democratic powers as Rep. Dan Rostenkowski (D-Ill.) and Chicago Mayor Richard M. Daley, who support the fee as a way to finance an urgently needed third airport for their city. Other big city interests, representing Los Angeles, Phoenix, and St. Louis, are also eyeing the $1 billion a year in annual revenues and the leverage that cash flow would provide for future bond issues.

At the same time, the Oberstar bill is crafted to attract support from rural members of Congress. The underlying legislation includes guarantees of an extended period of subsidies to small airlines that provide service to small towns.

The "Essential Air Service" program was established many years ago to promote service to areas that otherwise might have lost it as a result of airline deregulation. The program has long been targeted for elimination by the administration and the House Appropriations Committee. But the same legislation that initiates the passenger facility charge would remove the rural subsidy from the hazards of the annual appropriation process by authorizing long-term funding for it under the Airport and Airway Trust Fund.

Reps. Douglas H. Bosco (D-Calif.) and Norman Y. Mineta (D-Calif.), members of the Public Works Committee, hope to ground the ticket fee jet by eliminating it on the floor. "It's bad public policy," said Mineta.

Other critics warn that the fee, while providing funds for relieving congestion and crowding, could hurt passenger business. Bosco's office yesterday announced labor unions have begun lining up against the fee because the legislation fails to stipulate that construction financed by the charge would be subject to prevailing union wages.

Opposition is also expected from a contingent of Indianans who want the proposed new Chicago-area airport to be located in Gary. They contend that the passenger fees would give the Chicago Airport Authority a strong hand to locate the new facility within that city.

Airlines appear divided on the issue. Several that enjoy dominant positions in their hubs reportedly oppose the fee because it would finance expansion for competitors.

Staff writer Don Phillips contributed to this report.