Three weeks ago, City Councillor William H. Walsh revealed a side of himself that few of his colleagues had seen before.

Angered by what he claimed was an attempt to stifle his speaking privileges, Walsh embarked on a one-man crusade to block discussion of council business. Using privileges granted to all councillors under the city charter, the third-term councillor postponed action on no less than 11 council orders.

Although Walsh has never shied away from confrontation in his previous years on the council, during the present term he appears to have actively sought it out. While he has toned down his approach during the last two meetings, Walsh says the makeup of the current council has forced him to change his style slightly.

In previous years, Walsh tended to serve as a spokesperson for a strong conservative bloc that often dominated the nine-member council. Now that Walsh's conservative allies no longer control the council majority, the third-term councillor says he has had to adopt more agressive tactics.

"I have to yell a little louder to the mayor than in the past in order to be heard," Walsh says, discussing the charter-right incident. "I think I made my point," he adds.

Although the city's conservatives have two other representatives on the council--Sheila T. Russell and the indefatigable Walter J. Sullivan--neither speaks at council meetings on a regular basis.

That leaves Walsh as the lone voice defending the interests of real estate owners and other critics of rent control. And in recent weeks, Walsh has made sure that his voice has been heard.

On two occasions in January, for example, Walsh questioned City Solicitor Donald A Drisdell for more than two hours on details related to the repeal of a rent control ordinance. Although no colleagues claim Walsh intended to be disruptive, his persistence strained the patience of many on the liberal majority.

"It's clear that he can take a position and speak about it all night," says Councillor Jonathan S. Myers, who is backed by the liberal Cambridge Civic Association (CCA), a group which Walsh frequently opposes.

And although all 11 of the items Walsh postponed action on were passed at the next council session, some longtime Walsh critics--as well as a few city councillors--maintain that such tactics frustrate the democratic process.

"It struck me in those first few council meetings as a kind of haranguing of all of us," says Michael H. Turk, a leader of the Cambridge Tenants Union. "His filibustering only lengthened the evening, it didn't effect the outcome."

But filibustering, while annoying to those in the majority, can be an effective political tactic. Minority politicians in this country have often used the approach as a last-ditch effort to affect legislation.

And Walsh's allies and constituents say he has little choice. "They're going to gang up on Walsh and all he can do is use parliamentary devices," says John Natale, co-chair of the Small Property Owners Association (SPOA). "He's fighting a good fight against insurmountable odds."

"I think he's handled himself pretty well," agrees Sullivan, the council's senior member. "He's just got a different fight than his colleagues and he's doing what he has to."

But several city councillors say the tactic is not so much annoying as it is counterproductive to the interests of Walsh's own constituents and the city in general.