The White House plan to give selected federal officials bonuses of up to 20 per cent and free, extra life-time pension benefits is a "raid" on the government retirement system, according to the president of the biggest federal retiree group.

John McClelland, head of the 300,000 member National Association of Retired Federal Employees, said that NARFE would oppose the special pay and pension system that the Carter administration wants as an enticement for top career bureaucrats to join the Senior Executive Service.

The SES is a major feature of the Carter civil service "reofrm" plan now before Congress. Reform is necessary, the president says, to streamline antiquated federal hiring and firing practice help him proceed with reorganization of agencies.

The SES itself would eventually take in more than 9,200 top career and political appointees in grades 16 and above.

Executives entering the SES would give most of the job security they now enjoy. In return, they would be eligible for yearly bonuses, and the chance to move ahead faster.

McClelland's opposition stems from a March 20 column here. It pointed out that although the proposed bonuses would be taxable, the extra lifetime pension benefits - of between $750 to $1,000 a year - would not be.

The money to pay the extra, higher annuities to selected officials would come from the regular civil service retirement fund. That fund is made up of money that government workers and their employers' working careers. Under the SES proposal, officials who got bonuses would not have to contribute the normal 7 percent of income on that amount.

Under the SES the life-time pension for an executive would increase by $250 a year each time he or she got the maximum salary bonus of 20 percent. Those higher annuity benefits would not be available to federal workers below the grade 16 level.

McClelland feels the free, higher pensions for top executives would be unfair to other federal workers and the taxpayers who would have to pay for them.

The retiree group also believes, McClelland said yesterday, that what the president is doing is "proposing something for nothing for a particular group of employes. He wants to give them bigger retirement checks without paying for them. This runs directly counter to the concept of sound fiscal management."

McClelland also questions a proposal under the SES which would give early retirement to executives who were pushed out for "less than fully successful performance." The NARFE president says this amounts to using the retirement system "as a means of eliminating unproductive executives."

Top Civil Service Commission officials, who drafted the SES plan, defend the special retirement benefits for executives. They say it is common practice in the executive ranks of private industry and is an "effective management tool" for motivating outstanding employes to serve in higher-risk jobs.

CSC brass say that relatively few executives would qualify for the maximum 20 percent bonuses each year, and that while those beneficiaries would be getting what amounts to a partial "free ride" toward higher pensions, the costs are a drop in the bucket.

House hearings on the "reform" plan resume after the Easter recess, and much of the oppositition will center around the SES proposals.