BACK IN APRIL, when President Carter decided to raise the price for federal employee parking in government lots, congressional leaders said staunchly that they supposed free parking on Capitol Hill would have to go, too. That must have been a momentary lapse, because since then the legislative branch has moved toward that particular bit of self-sacrifice with all the speed of a parked car. The main activity on the congressional parking front continues to be the fierce jockeying for places among thousands of staff members.

So it was good to see Sen. Charles H. Percy bring up the subject last week. Mr. Percy was one of about two dozen senators who wanted to end this notorious freebie two years ago. Now he is trying to advance a bill that would include Congress in a nationwide policy of charing commercial rates for parking at government lots, along the lines of the president's plan for the executive branch. The hearing last week brought out some legitimate questions about the overall approach, such as its effect on lower-salaried workers who have no public transit or car-pool alternatives. But those objections do not apply to parking on Capitol Hill, where mass transit service is quite good - and where so many parking stickers go to people who can surely afford to pay.

The hearing did bring out one convert, Sen. Pete Domenici (R-N.M.), who said that "the energy crisis and simple fairness" had persuaded him that the government should no longer "give its parking spots away." But he may have touched the most sensitive spot when he spoke of public resentment of the "goodies" that federal officials give themselves. We hope that sense of embarrassment spread through Congress as thoroughly as congressional parking lots have covered Capitol Hill. Self-evidently the parking perks are not going to be eliminated - until they get costly at home.