A bridge or a prison? Which is the most appropriate structure to bear the name of a state legislator whose 30-year career ended in a scandal of tax evasion and ethics violations charges?

Massachusetts state legislators will have to make that decision if two competing bills make it to the House floor.

A moral controversy is underway after Cambridge State Representatives Timothy J. Toomey and Alvin E. Thompson proposed a bill last week which would name a Cambridge bridge after Charles F. Flaherty, the former Speaker of the House, who stepped down in disrepute earlier this year.

Flaherty resigned after pleading guilty to federal tax evasion and state ethics violations for accepting illegal gifts. He was fined $25,000 and given two years probation.

But the Alewife Brook Bridge is not the only structure vying for the somewhat dubious honor of carrying the Flaherty name.

The political action group, Citizens for Limited Taxation & Government (CLTG), hopes to find a sponsor for a bill that would name the state prison in Concord for Flaherty instead.

"We think people who have pled guilty to avoid being indicted on other counts shouldn't be honored," said Barbara Anderson, co-director of CLTG. "If they're determined to name something after him, (we) thought the state prison would be a better image."

Anderson said she thought Flaherty, as Speaker of the House, belonged to the state as a whole and not just to Cambridge. She said that if Flaherty is honored, "[it] should be something that reflects his position as Speaker of the entire House, something that will remind us of him long into the future."

The CLTG also believes naming the bridge after a criminal sends the wrong message to children. "If [our efforts] save one child from a life of crime, it will be worth it," Anderson said.

But a spokesperson from Rep. Thompson's office said the way Flaherty's career ended is irrelevant to their aims in trying to name the bridge after him.

"This bill has nothing to do with [the circumstances of Flaherty's resignation]," said Daphne Abeel, a legislative aid at Thompson's office.

"It's being proposed to honor him for his service to the city," she said. "[Flaherty] is still held in high esteem by legislative colleagues."

But at least one former constituent of Flaherty felt the former speaker is unworthy of the honor.

Stan Burrows, a longtime Cambridge resident who said he had voted for Flaherty numerous times, said a prison would be a better namesake than a bridge. But he thinks Flaherty doesn't deserve to have anything named after him.

"They should name the bridge after [former Harvard president Derek] Bok, someone who's actually accomplished something."