More than 300 members of the Hotel and Restaurant Workers Union demonstrated in front of the District Building yesterday against a proposal to drop funds for the proposed down-town convention center from the 1978 city budget.

D.C. City Council member Nadine Winter (D-Ward 6), a supporter of the convention center, he said that she would ask the council today to withdraw the city's request for $27 million in start-ups funds for the project and to add the request to the 1979 budget.

In that way, Winter explained to the demonstrators, a deadlock between the House and Senate that is blocking adoption of the 1978 budget could be resolved.

Ron Richardson, secretary-treasurer of the Union's 10,000-member Local 25, rejected Winter's approach, saying it would weaken the case for the center, which he said would produce 5,000 or more hotel and restaurant jobs.

Mayor Walter E. Washington, Council Chairman Sterling Tucker and council members Marion Barry (D-At Large) and Arrington Dixon (D-Ward 4) spoke of appeared at the demonstration and reaffirmed support for the project.

In another development, five business groups issued a joint statement reaffirming support for the center. They are the D.C. Banker Association, the Metropolitant Washington Board of Trade, the Washington Area Convention and Visitors Association, the D.C. Chamber of Commerce and the Hotel Association of Washington.