Moving to fill a gap in District of Columbia law, Mayor Walter E. Washington has asked the City Council to enact emergency legislation tonight that would put Mayor-elect Marion Barry's transition team on the city payroll.

The same legislation would authorize the city to pay for secretarial help and postage for Mayor Washington and City Council Chairman Sterling Tucker for three months after they leave office Jan. 2.

" . . . The incumbent (outgoing) mayor must be in a position to provide the mayor-elect with the services and facilities that are necessary to prepare for the assumption of executive power," Washington wrote in proposing the legislation. "Current law does not specifically authorize the expenditure of funds for such purposes."

Tucker introduced the bill in the council, where it is scheduled for action tonight.As emergency legislation, it would become law immediately, and would remain in effect for 90 days. The mayor has suggested the adoption of similar permanent legislation applying to future transitions.

The bill also would permit the mayor to assign city employes temporarily to the mayor elect's transition team, and to provide office space, typewriters and other equipment, and transportation and postage.

January's shift of power from Washington to Barry will be the first full government transition in the District of Columbia since 1874.

In that year, the D.C. changed from a territorial government to a governor and legislation to a three-man, presidentially oppointed board of commissioners, always with overlapping terms.

In 1967, President Johnson reorganized the city government and appointed Washington as a single commissioner with the courtesy title of the mayor. Washington continued in office as the elected mayor with transition to home rule government in 1975, but was defeated for the Democratic renomination by Barry last September.

After Barry was elected on Nov. 7, he created a 13-member transition team with offices in the National Theatre Building, but found no provision for paying them from public funds.

As proposed, the new legislation would pay those transition office staff members who are not already District of Columbia employes at the daily rate provided for civil service employes doing similar duties. Temporary employes would not be covered by city retirement programs or fall under the Hatcht Act, which restricts political activity.