The signs must stop, Pittsburgh Council members said yesterday, as they crafted legislation that would put an immediate halt to construction of billboards within the city limits.

As talk circulated about expansion of a landmark Mount Washington sign, disagreement festered over a planned Downtown billboard, and discussion of a placard swap in Lawrenceville continued, council members charted a three-pronged assault on outdoor ads.

They'll ask the mayor for a moratorium, grant themselves approval power over signs and pile on to Councilman Patrick Dowd's legal challenge to the proposed electronic billboard at a new Downtown transportation center.

"Stop the train," said Council President Doug Shields. "This council unfortunately must assert itself."

On Tuesday, state Sen. Jim Ferlo, D-Highland Park, sent an e-mail to city officials expressing concern over what he said was a proposed doubling of the Bayer sign -- formerly the Alcoa sign -- on the north face of Mount Washington. He suggested a sign moratorium, saying in an interview that council should revise the code governing signs that he crafted as a councilman in 2001.

Bayer and Lamar Advertising, which owns the Mount Washington sign, said they don't have plans to expand it.

Council's concern about signs was spurred by a December decision by administration officials to allow a 1,200-square-foot digital billboard on the new Grant Street Transportation Center without public bids, votes or hearings.

Council and administration officials led by Urban Redevelopment Authority Executive Director Pat Ford have disagreed on whether the current code requires public hearings and votes for that sign. Five council members have said a public process is required, while Mr. Ford has said it is not, because Lamar plans to replace six vinyl signs with one digital one.

"Until and unless we can clarify that, we don't want any more signs going up in the city," said Councilman Bruce Kraus, who is expected to be the prime sponsor of billboard legislation to be introduced Tuesday.

Council can't force the mayor to declare a moratorium on signs, and his office had no comment yesterday on council's plans to ask for one.

Council's plan to introduce a zoning code amendment giving itself a vote on any sign replacement agreements, though, would instantly alter the playing field. That's because proposed zoning changes take effect immediately upon introduction and remain in place during a lengthy process of hearings and votes.

That would put on ice an effort by Lawrenceville United Executive Director Tony Ceoffe to negotiate a deal with Lamar to slash the number of vinyl billboards on Butler Street in return for two new digital signs, near the 40th Street Bridge and the entrance to the Pittsburgh Zoo & PPG Aquarium parking lot.

"We can't move forward now," Mr. Ceoffe said when told of the planned council action. "Any agreements, or any kind of conversations we'd have with Lamar at this point are moot, because now we have to wait for City Council. We're done."

He said he worries that Lamar may exercise the right to modernize its billboards without any public approval, as long as it doesn't increase their size. He said he hopes he can instead work with the company to ensure that the overall number of billboards decreases during any move toward digital signs.

Several council members huddled with former city lawyer Hugh McGough -- now in private practice -- to weigh other actions. Some may join Mr. Dowd's Zoning Board of Appeals challenge to the Grant Street billboard permit, or seek a Common Pleas Court injunction to put a hold on that sign.