Benedetti said that more is being spent on indigent defense because cases are becoming more complex and lawyers are being asked to do more, such as explaining immigration matters, or fighting cases that involve mandatory sentences. One example is district attorneys’ expanded use of the state’s dangerousness laws to keep defendants charged with gun crimes detained pending trial.

“The court is saying you have to do this, and that drives up costs,’’ Benedetti said.

In 2005, a legislative commission — known as the Rogers Commission — recommended the raises as part of a broader strategy to overhaul the public defender system. The commission also recommended ways to cut costs: better screening to determine which defendants qualify for public counsel, and the decriminalization of minor crimes, to lessen need for a lawyer. Also, the group recommended hiring more staff lawyers to offset the use of private attorneys, to control costs after the raises.

Another recommendation the commission made was for the public counsel agency to reduce the number of hours a private attorney can work each year, from 1,800 to 1,500.

But in the five years since, a Globe review has found, little has been done beyond the boost in pay, resulting in the system costing far more than estimated.

“We’re in the middle of a full-blown fiscal crisis, and just saying you have a constitutional obligation [to poor defendants] and you’re spending the money wisely is not a good answer,’’ said Michael Widmer, president of the Massachusetts Taxpayers Foundation, who participated in a symposium with prosecutors and public defenders last month at Northeastern University. He described the system as writing a blank check for defense lawyers.

“We have an open-ended system that is not sustainable and not fair in the context of the state’s finances, and it needs to be reined in.’’

The Globe review found that several firms have made the defense of the poor a key part of their practice.

One law firm of two people, for example, has received $1.2 million in payments from the state over the last five fiscal years — an average $123,481 a year for each lawyer.

“The way we operate here, there’s no cost containment, there’s no controls, and it’s an unsustainable system,’’ said Suffolk District Attorney Daniel F. Conley, arguing that private lawyers are making far more off the system than the average homicide prosecutor makes, about $75,000 a year.

“We believe it can be done more cost-effectively,’’ Conley said.

But the effort to cut down on spending is bound to confront a strong lobbying effort by private attorneys who virtually shut down the court system seven years ago by refusing to take new indigent cases without the new wages.

“This is going to be opposed by a special-interest lobby of some 3,000 lawyers, so it’s not going to be easy,’’ Conley said.

In several interviews, Benedetti, of the public counsel agency, argued that the state will not see the cost savings the governor has predicted. He forecast in a report to state officials last year that it would require 746 more staff attorneys than he has now — for a total of about 1,000 lawyers — at a budget of $86.6 million to handle 50 percent of his agency’s total caseload, or about 145,000 cases. His office would still require the use of private attorneys to handle the remaining cases.

By contrast, the 11 district attorneys across the state have about 710 prosecutors and as many support staff who handle more than 300,000 cases, with a total budget of $92 million, according to the Massachusetts District Attorneys Association. Supporters of the public defender system argue that the analysis of spending on prosecutors does not factor in the millions of dollars spent on other aspects of law enforcement.

The private lawyers and public counsel agency officials argue that the spending is needed to guarantee constitutional rights for poor defendants by providing them adequate representation if they face the possibility of jail time. Overworking a staff attorney would erode the quality of representation, they say.

Central to the debate between prosecutors and defense attorneys is whether the state would save money by reducing the use of private lawyers and hiring more staff attorneys, which also includes paying benefits and office space. Under Patrick’s plan, private attorneys would still play a role, but their use would be drastically limited.

Critics of the excessive use of private attorneys argue, citing the Rogers Commission, that the public counsel system was not set up to pay private attorneys’ full salaries. According to the agency, 51 percent of the 3,026 lawyers who billed for services in fiscal 2010 made more than $50,000. In comparison, a starting prosecutor and staff public defender each makes less than $40,000 — their only source of income.

Milton Valencia can be reached at mvalencia@globe.com; Matt Carroll can be reached at mcarroll@globe.com.