When Federal Reserve Chairman Paul Volcker steps before the National Association of Federal Credit Unions (NAFCU) convention this morning to deliver the keynote address, he may feel like Daniel facing the lions.

Volcker is also chairman of the Depository Institutions Deregulation Committee, an interagency group whose actions have raised the hackles of credit union executives. Joseph Cugini, chairman of the Credit Union National Association, recently accused DIDC of "overzealous inflexibility".

The primary object of their ire is a DIDC proposal to equalize the rates on transaction accounts paid by different financial institutions. At the moment credit unions may pay up to 7 percent on their share draft accounts, a form of interest-bearing checking account, whereas banks offering NOW accounts, which are almost identical to share drafts, pay only 5 percent.

The question is whether to increase the interest rate banks can pay to that of credit unions, reduce the rate credit unions can pay to the banks' level or compromise. Credit unions have estimated that reducing their rate from 7 to 6 percent would cause shareholders to lose $5 million. More serious, credit unions that do not already offer share draft accounts would be discouraged from getting into the business. Approximately $1 billion of credit unions' $57 billion in deposits is in share draft accounts.

Credit union officials are also unhappy about the Fed's proposal to impose nonearning reserve requirements on share draft accounts to bring credit unions into line with other financial institutions that already have reserve requirements on their transaction accounts. They were dissatisfied with DIDC'S action in raising effective ceilings on certificates of deposit to 9.5 percent. They oppose DIDC's suggested ban on premiums -- the gifts frequently offered as an inducement to open a new account or add to an existing one.

NAFCU president John Hutchinson termed the regulation "meddling" in the operations of financial institutions. He, like many other thrift officials, voices the opinion that DIDC is not carrying out its congressional mandate to diminish the regulatory burden, but doing just the opposite.

Credit unions have just experienced their worst 18 months in history, according to James C. Barr, executive vice president of the Credit Union National Association, a trade organization. During that period, when interest rates skyrocketed, credit unions were at a competive disadvantage because money market mutual funds and savings and loans could pay higher interest rates on deposits. Also, they were legally unable to charge more than 12 percent interest on loans. As a result, funds dried up.

Statistics compiled by the National Credit Union Administration, their government regulator -- and also a member of DIDC -- show that annual growth in deposits, whch had climbed to 15 percent in 1978, sank to a mere 1.7 percent between January and May 1980. Loan activity during this period decreased by 7 percent over the corresponding five-month period last year. Locally loan activity was off 10.8 percent at Maryland credit unions, and 8.5 percent in the District in the first four months of the year. Even in the depths of the 1974-75 recession, credit unions experienced 11 to 12 percent growth.

Interest rates on deposits are currently competitive with money market funds and in some surpass those offered by savings and loans. Credit unions are now able to charge up to 15 percent. Now that credit unions are getting back in the ball game, the industry fears that new regulations -- together with the recession -- will dampen recovery.

NCUA predicts that loan activity will remain stagnant during the second half of the year or even decline further. Demand will be virtually nonexistant except for emergency measures, one economist said. CUNA's mid-year forecast, on the other hand, exudes optimism. It predicts savings will expand at an annual rate of 12 to 15 percent, and loan growth will range between 8 and 15 percent.

Barr predicts a "significant market shakeout" in this decade resulting in fewer institutions. The trend toward consolidation becomes apparent in NCUA's statistics on the growing number of merger applications and liquidations. To date in 1980, there have been 160 merger applications, compared with 139 in the same 1979 period. This year so far 149 credit unions with $47.3 million in assets have been involuntary liquidated by NCUA; last year over the same months, the figure was 135 with $20.6 million. There have been 112 applications for new credit unions this year, compared with 167 last year.

The largest federal credit union in the country is located in the Washington area. Navy Federal Credit Union has assets of $777.6 million. Its president, Vice Admiral Vincent A. Lascara, was recently elected secretary of NAFCU. The other large credit unions are in the Pentagon ($446.7 million in assets), Andrews Air Force Base ($121.7 million), the State Department ($105.9 million), the National Institute of Health ($75.6 million) and the Bank Fund Staff ($72 million).