The current political and social crisis facing the United States is the sharpest challenge to democracy since the Depression of the 1930s and demands stern measured, Felix G. Robhatyn, a leading New York investment banker, warned Washington business leaders yesterday.

Rohatyn prescribed temporary wage-price controls, deep and permanent budget cuts, an end to the upward indexing of federal benefits for inflation, a large gasoline tax and the creation of a bipartisan advisory committee to chart national economic strategy. He also advocated bargining with the Organization of Petroleum Exporting Countries for a stable oil supply and prices.

His speech to the Federal City Council at the Madison Hotel repeated points he had made in earlier addresses elsewhere and in published articles.

Rohatyn, a senior partner in the banking firm of Lazard Freres & Co. and chairman of New York state's Municipal Assistance Corp., also heads a financial advisory team to the District of Columbia government. He didn't discuss the District's financial crisis.

"We are facing a political and social crisis of major dimensions, challenging democracy here at home as nothing has done since the 1930s," Rohatyn declared. "The social fabric today is not as resiliant as it was then. In many parts of the country it is taut as a bowstring, tight as a drum.

"If pushed hard, it won't give but will come apart," Rohatyn declared. "It isn't a risk worth taking."

Treasury Secretary G. William Miller, a head-table guest at the luncheon, declined to comment on Rohatyn's remarks.