A group of Prince George's County activists, stalled in its effort to have voters review a county cable television franchise by referendum, has filed suit against the Board of Elections supervisors to force acceptance of the 5,100 signatures already collected.

On Jan. 12 the three-member elections board threw out the signatures, saying the petition was worded improperly. The group, called Citizens Against Backroom Legislation (CABL), organized the petition drive to allow voters to review a controversial cable television franchise award on the ballot this November.

The activists acknowledged that they will be hard pressed to collect the remaining 5,000 signatures needed by a Feb. 22 deadline.

"We've collected, quite frankly, not a lot of signatures" since the election board decision, said CABL organizer Del. Thomas Mooney. "It's either the sub-arctic temperatures or the six feet of snow."

Joseph W. Johnson, a CABL volunteer, added, "There's no doubt about it, our backs are against the wall. We're in for a tough month but I think we can make it. We always have," he said, referring to past petition efforts that have been challenged by the elections board.

The CABL group aims to overturn the franchise award to Storer Cable Communications of Prince George's County, a company represented by former county executive Winfield M. Kelly Jr. Storer won the right to build the county's northern area cable system last fall by a vote of the County Council.

CABL denounced the elections board's decision as political and had planned to file suit immediately to have the decision overturned. Their efforts were delayed when their attorney, state Del. David Bird, refused to continue to represent the group, citing his responsibilities as a state legislator. Other officials said privately that Bird had been pressured not to participate by municipal leaders in his district who also awarded their local cable franchise to Storer, but Bird and other CABL volunteers denied this. Another attorney, James F. Vance of Camp Springs, recently agreed to represent the group.

Storer, meanwhile, is attempting to join the suit as a codefendant with the Board of Elections. William Meyers, a former elections board attorney who represented Viacom, a losing cable company during the franchise selection process, will represent Storer in its effort to join the petition suit. Meyers had denounced the council's selections as politically motivated, but said Wednesday, "I didn't have any particular criticism of Storer. I did have a criticism of the process."

Meyers said he agreed to take the case because, "We're lawyers. We get paid to represent clients."

Meanwhile, Storer has embarked on its long-promised counterattack on the petition effort. The company began running a series of full-page advertisements last week in county newspapers bearing the terse warning "DON'T SIGN THE PETITION" and the advice that those who sign, "will add YEARS to the wait" for cable television in the northern area.

Storer officials said that preliminary work on constructing the county's cable system would continue. However, Dolores Early, director of the county's cable commission, said that the county's legal negotiations with Storer have stopped until the referendum issue is resolved.