Jina Alexander and John Larson, leaders of the Loudoun County Taxpayers Association, had been giving the dickens to the county Board of Supervisors for a whole year.

You're spending too much money, taxes are too high, the county government is getting out of hand, their lectures to the supervisors went.

According to Alexander and Larson, the oft-repeated only made the supervisors' eyes glaze over. Not only did the supervisors not respond with an economy program - they even slapped a 5-cent increase on the real estate tax rate while other local jurisdictions were lowering theirs or at least holding the line.

But Io, eyes are glazed no more. Suddenly they are alertly scanning the landscape occupied by restive taxpayers.

Two weeks ago - the same day 300 protesting taxpayers gathered in the Courthouse Green in Leesburg - the supervisors passed a resolution calling for a review of what an across-the-board 10 percent reduction in spending would mean. The next day the supervisors appointed a committee to review the work of the county assessor's office, which has reappraised some houses from 75 to 100 percent higher than they were valued in 1977. Significantly, the committee will include three homeowners - an obvious attempt to try to close the widening gap between local officials and their taxpaying constituents.

In Fairfax County, there has been an even more substantial effort to directly involve the citizenry in issues of spending. No less than three citizen committees are being created - one to look at social needs, one to look at the tax structure and the third, efficiency in government.

Local officials don't like to say so publicly, but one of the prime reasons they're now eagerly soliciting citizen involvement is to be able to show disgruntled taxpayers 1) that hefty cuts in services or programs would be extraordinarily difficult, if possible at all, and 2) the source of many of the problems is not local but in Richmond, where the General Assembly makes laws.

Loudoun County Supervisor Frank Raflo, who has represented the Leesburg area for two terms, points out that the board, which has been accused of free spending, approved only a 4.1 percent increase in expenditures for the fiscal year that began July 1. "We feel that's pretty conservative," he said, adding that the demand for services, all of which are costly, has been steadily growing as the county urbanizes.

Fairfax County Executive Leonard L. Whorton thinks the citizen committees will discover how little power localities have in giving a break to the elderly and other homeowners whose real estate taxes consume a disproportionate part of their income.

Not only does Richmond decide who shall get tax breaks and how much, it also sets increasingly higher standards for services through mandated programs. But local officials complain that the costs of these mandated programs - smaller classroom size is one frequently cited - sometimes outstrip their ability to raise revenue. The only alternative they then have, argue the local governments, is to raise taxes. But the payers of those taxes blame the local supervisors, not Richmond.

Raflo's most immediate example is the Loudoun Circuit Court's order, backed up by the State Supreme Court, that the local government provide better court facilities. Twice Loudoun voters turned down a referendum that would have permitted a bond sale to pay for the estimated $1.6 million renovation of the present courthouse. Still the judge said that the supervisors had to raise the money. If they didn't, they could go to jail for contempt.

While this wrangling continued, the cost of the proposed renovation escalated - to $2.7 million. It was the supervisors' desperate attempt to pay at least half of this amount through a 5-cent increase in the tax rate that helped trigger the revolt that took tangible form on the Courthouse Green.

Redirecting heat from taxpayers to Richmond is difficult. The state capitol is much less convenient than the supervisors' board rooms. In addition, the state legislators meet for only a month or two annually, while the supervisors meet almost all year round.

One solution, as local officials are beginning to realize, is that they themselves may have to apply more heat. Thus Loudoun officials worked furiously to get a big turnout of their counterparts in other jurisdictions at a Leesburg hearing by the legislative subcommittee looking at the impact of state-mandated programs. The audience of 75 included officials from counties as far away as Campbell, Roanoke, Hanover, Chesterfield, York and Stafford.

Local officials aren't about to hold a rally on the Courthouse Green, but some of them think this is the next best thing.