Gloucester Mayor Carolyn Kirk, less than a month into her first term, is making good on her promise to shake up local government. One of her boldest, and most controversial, moves is her proposal to replace the city's in-house legal department with Kopelman and Paige, a Boston firm that specializes in municipal law.

It might be a good move for the city. But so far, the mayor has not made nearly enough of a case for it. Skeptical city councilors and a number of other local officials are wise to urge that the city proceed with extreme caution, if at all.

There are some clear advantages to the city having an entire law firm at its disposal. As good as City Solicitor Linda Lowe and assistant Suzanne Egan may be, there is no way for two people to match the range of expertise offered by a 60-lawyer firm. And the mayor would simply be following the lead of many other cities and towns - Kopelman and Paige is employed by about a third of the municipalities in the state, including Essex, Danvers, Amesbury and Newburyport - and Kirk says the firm comes "highly recommended."

Another attraction is that the city would no longer have to maintain a department with employees who draw salaries and benefits no matter how much legal work there is to do - at a price this year of $230,000. Instead, the city would pay only for the services it uses, at $150 an hour.

As critics have noted, there is no guarantee that will save the city money - if it needs more than 1,500 hours of legal services, it will spend more than it does now. But there is also no way to calculate the savings that might result if that expertise helps to avert lawsuits, settle grievances more quickly or produces labor contracts that are more affordable. In that case, the savings could run into the millions.

Still, there are very important unanswered questions about how well the city will function with no in-house legal department.

How accessible will an outside firm be? Will it be as easy to get quick advice on a minor matter as it now is? Will a board or commission member have to make five calls to get to the "right" attorney, instead of simply dropping by Lowe's office? What will the city lose - or perhaps gain - by not having a staff attorney who knows the local political landscape? What will it lose by not having a person with some institutional memory? Will what used to require just a two-minute conversation with Lowe suddenly become a $150 billable hour?

Even more significant, what happens if Gloucester has a legal conflict with another community represented by Kopelman and Paige? That is, in fact, what is happening right now. Essex, represented by the firm, is threatening to sue Gloucester over sewer bills. Kirk is now negotiating a possible settlement with the town, which means negotiating with the firm she is looking to hire. That raises serious conflict-of-interest questions right now, and would raise more if the firm was representing both communities.

In short, city officials - the mayor and council together - need much more information about how and how much the city uses legal services to determine whether an outside firm is the way to go.

A final cautionary note to the mayor is to remember that a law firm is there to offer advice, not directives. Kopelman and Paige has a reputation for opposing openness in government. That is a stance that is bad anywhere, but would be particularly bad in Gloucester, where there is a need to restore trust in local government.

In Newburyport, for example, the firm advised Mayor John Moak not to turn over documents regarding the suspension of a police officer, even though the suspension had to do with professional conduct on city time. The advice runs counter to an advisory opinion from state Supervisor of Public Records Alan Cote, based on a ruling by the state Appeals Court.

Local officials should, of course, seek the best possible legal expertise for the city. But they must also keep in mind that they, not a law firm, will be held responsible for the results of decisions based on that advice.

This is a very big decision. It should not be made hastily.