Drip, drip, drip.

Like Chinese water torture, the House Republican approach to issues affecting federal employees is a steady stream of niggling hits at their pay, benefits and now their labor organizations. There are bills to cut the number of federal workers, further extend their pay freeze, reduce their annuities and make them pay more for their health benefits.

Last week, a House subcommittee held a hearing on “rightsizing” the federal workforce, without ever showing it is the wrong size. The latest drip on this list fell Wednesday as the subcommittee considered legislation that would severely limit the ability of labor representatives to do union work on government time.

This practice, known as “official time,” is the target of legislation introduced by Rep. Phil Gingrey (R-Ga.). His bill would stop the use of official time for collective bargaining, and he encouraged the panel to amend the measure so official time would be eliminated all together.

Gingrey said he “in no way, shape or form” wants to take away employee rights, a statement that John Gage, president of the American Federation of Government Employees, who also testified, doesn’t believe for a minute.

“The issue,” Gingrey insisted, “is who pays.”

In testimony submitted to the subcommittee, Gingrey said, “Official time is not fair to the government or the taxpayer and works solely to the benefit of labor unions and employees who serve as its representative or steward. With an extraordinary amount of federal employees authorized to use 100% official time on behalf of their union, the federal government loses the immensely valuable civil service for which he or she was originally hired to perform. Additionally, taxpayers pay for absolutely no official productivity on their own behalf while federal employees use official time.”

No one knows, by the way, how many employees are authorized for 100 percent official time, a failing of the Office of Personnel Management’s reporting on this program. So, “an extraordinary amount” could be one or two if you don’t want any official time at all.

There is a theoretical argument against having the federal government pay union reps for work that sometimes is in opposition to the wishes of government managers. And the workforce might have reason to wonder whether their reps are too cozy with the management that pays their salaries.

But these valid concerns don’t take into account the reasons Congress provided for official time. Those reasons are more involved than theoretical or ideological objections would indicate.

The main reason for official time is that Uncle Sam requires unions to represent employees who are not members and who pay no fee for the union services they use. So he made a deal with organized labor. It provides service even to those who don’t pay for it, and the government allows some employees to be paid by the government for time they spend on certain union activities.

Sam could do away with official time if he said all employees in a bargaining unit must join the union that represents them. But this closed-shop approach is a non-starter in the federal government.

It’s also important to know that not all activities are covered by official time.

Union members on official time cannot sue Sam or conduct internal union business, such as attending conventions and participating in union elections. But OPM says they can represent employees in grievance and disciplinary actions, negotiate contracts, speak for workers in meetings with management, participate in labor-management workshops, assist in the implementation of workplace initiatives and help agencies communicate information to employees.

Despite strong support in the House, it’s doubtful that Gingrey’s bill and many of the others aimed at federal employees will become law as separate pieces of legislation. The Democratic-controlled Senate and the White House wouldn’t stand for it.

But federal employees and their unions would be foolish if they take too much comfort in the bosom of their Democratic friends. Some of the measures they oppose but are pushed by Republicans — and the bipartisan National Commission on Fiscal Responsibility and Reform — could become law if included in larger measures that Congress and the Obama administration can’t afford to reject.

Case in point: When President Obama needed to sweeten a budget deal with Republicans that kept the government from shutting down this spring, the District’s right to use its own taxpayer money to fund abortions for poor women became expendable.

Republicans have several employee-related measures that easily could be thrown into a larger compromise package that Democrats would have no real option but to approve. Federal employees have lots of strong supporters among Democrats on the Hill and in the White House, but that’s no guarantee against being sold out.

This is not a prediction, just a lesson in recent history. Perhaps the Republicans are spending so much energy targeting federal workers simply to score ideological points. Perhaps they are truly interested in efficient government. Perhaps they have a deeper strategy that won’t become apparent until later.

Whatever the reason for their approach to federal employees, “I think it is disgraceful. I really do,” said Rep. Stephen F. Lynch (Mass.), the top Democrat on the panel. “We ought to stop trashing them.”