Protesting what they claimed were heavy-handed tactics, backers of Sen. Edward M. Kennedy's presidential campaign appealed to the Democratic National Committee yesterday to grant their candidate more Virginia delegates to the party's national convention in August.

Kennedy supporters, most of them from Richmond, came armed with lawyers and allegations that they were cheated of their rightful representation at local and state political meetings held this spring.

A special hearing officer took testimony at committee headquarters at 1625 Massachusetts Ave. NW throughout the day on three separate challenges filed by Kennedy's campaign staff in Virginia.

While conceding that the appeal would make little difference at a convention President Carter has virtually locked up, Kennedy's supporters said they were pressing their claims as a matter of principle -- and to guard against future abuses in the delegate selection process.

"There's a feeling that everthing was managed and very controlled by the Carter people," complained Jeffrey Clark of Chesterfield County.

Clark and other Kennedy backers have challenged several procedures used in selecting delegates from the Richmond, Chesterfield and Danville areas of the state. They contend their candidate would have received more delegates but for the pro-Carter bias and practices of state party leaders.

In Clark's case, he and others were sent home from the county Democratic meeting after its chairman ruled the Kennedy camp did not have enough members to elect their own Kennedy delegates.

Party rules required that presidential candidates receive the backing of 20 percent of local Democratic mass meetings in order to elect delegates to congressional district meetings.

But Clark and other Kennedy supporters said the chairman had initially allowed them to merge with uncommitted Democrats to form a caucus, then changed his mind as the uncommitted caucus was about to elect delegates that included some Kennedy supporters.

Instead, Clark said, the Kennedy backers and uncommitted people were told either to join the Carter caucus or go home. The Kennedy people went home -- and filed the formal challenge that was heard yesterday.

Unless the committee hearing officer rules otherwise, Kennedy will have only five of Virginia's 64 delegates at the national convention.