D.C. Mayor Walter E. Washington's proposal to turn the enforcement of parking laws over to civilians is being blocked in the City Council and almost surely will not go into effect as planned Oct. 1, creating a potential gap of $14 million in next year's city budget.

David A. Clarke (D-Ward 1), chairman of the council's judiciary committee, said he is holding up action on the parking measure in a dispute with the mayor over the long-delayed publication of the Municipal Code, which includes the city's parking and traffic regulations.

Clarke said he was not willing to turn enforcement of parking laws over to civilians unless there is "a compilation of exactly what it is . . . the new officials are to enforce and adjudicate." He said the rules are now scattered through half a dozen different volumes.

Under the mayor's proposal, a force of 50 civilian ticket writers would take over much of the parking enforcement now done by the police department, and five civilian hearing officers would replace Superior Court judges as the setters of penalties in contested cases. Other enforcement actions, including increased "booting" of cars with accumulations of unpaid tickets, would be stepped up.

Douglas N. Schneider Jr., the city's transportation director, testified before the House District Appropriations Subcommittee recently that the new program would cost about $6 million a year to administer, while bringing in an estimated $20 million additional revenue - a gain to the city treasury of $14 million.

The $14 million is counted in the budget for the 1979 fiscal year now pending before Congress. Without it, the budget would be unbalanced by that amount, or would have to be cut.

Although there is still enough time for the council to pass the now-blocked bill to authorize the shift on Oct. 1, the start of the program on that date probably is already doomed by the timing and nature of the congressional budget process.

Congress does not appropriate funds for programs that are yet authorized by law.

Both houses of Congress are expected to act by June on the city's budget for 1979, which means the parking program, once is approved, probably would have to wait for a supplemental appropriation bill at some uncertain future time.

Clarke said he would not be rushed by a budgetary argument. He said the mayor promised in December 1976 to have a Municipal Code compiled by early 1977, but has failed to keep his word.

Martin K. Schaller, executive secretary of the D.C. government, said 20 law students and five clerks will be hired this summer to compile the code. He said Clarke's holding of the parking measure hostage to its completion was unreasonable.

John R. Risher Jr., the city's corporation counsel and chief legal officer, said he agreed that the Municipal Code, is needed, but disagreed with Clarke's contention that the new parking program depends on its publication.

Portions of the proposed parking bill that deal with transportation matters have been approved by the council's transportation committee. However, they cannot be acted upon by the full council until the judiciary committee also acts.