The day after news broke that District Attorney Jeff Rosen had suspended a Santa Clara County prosecutor for misconduct, the union that represents prosecutors struck back.

The Government Attorneys Association announced Wednesday it had filed a grievance last month against Rosen for unfair labor practices. The grievance doesn't mention the DA's one-month unpaid suspension of Daniel Carr, who lost $16,500 in salary.

But it focuses on the volatile issue of how Rosen has been publicly handling both discipline and promotions. Carr, who is not related to former District Attorney Dolores Carr, has filed an appeal and is seeking a salary reimbursement because he claims his conduct preparing for a gang trial was normal practice by a number of his colleagues.

The tit-for-tat reflects an intensifying power struggle within the office between the district attorney elected on an ethics platform and union leaders accustomed to more lenient supervision of the rank-and-file.

On Wednesday, county labor relations officials rejected the grievance but agreed to discuss the issues it addressed with the union.

The grievance and supporting documents offer some details about the struggle between the two sides.

Shortly after Rosen took office in 2011, he signed a "Letter of Understanding" he inherited from the previous administration, promising to abide by several "quality of life" policies, including how to handle disciplinary matters and promotions.

A breakdown

But once prosecutors in his office agreed a few months later to a new labor contract, the provisions that weren't included in that contract were no longer legally binding. However, the DA's office stuck by them until last month, when negotiations between the union and Rosen apparently broke down. That schism appears to coincide with Rosen's final decision to suspend Carr for the maximum period possible, the first time he had suspended anyone for that long since he took office in 2011.

The union claims Rosen refused to meet and confer on the issue unless they stopped publicly criticizing him to other labor leaders and law enforcement officials.

But Rosen said Wednesday that his concerns arose from an incident in which union leaders called 14 minority bar association representatives and urged them not to attend a crucial meeting with Rosen about improving diversity in the office because of his stance toward labor. Twelve attended anyway.

Now, the union claims Rosen contends he is no longer obligated, for instance, to notify prosecutors within 45 days about promotions. Prosecutors' salaries, which range from about $85,000-$90,000 to about $195,000, depend on those promotions.

However, Rosen said Wednesday that everyone who has applied for a promotion has gotten one -- in a timely manner.

Two-step process

The provision of most concern to the union, however, has to do with which top executive in the office gets to investigate alleged wrongdoing. Under the Letter of Understanding, the executive who oversees the unit takes charge unless there is a conflict of interest. Rosen said there are good reasons why that executive occasionally might not be the right person to conduct the investigation, including they may have witnessed the alleged misconduct, be out of the office or have too much other work to do.

The Letter of Understanding calls for a second official to review the recommendation made by the first executive, hold a hearing on the matter with the person being disciplined and their attorney, if they have one, and make a second recommendation to Rosen -- often a softer punishment. Now, the DA does not have to assign a second executive.

But Rosen said he will stick to the two-step process, which is prevalent in the county even though merit system rules do not require it. "The reason is, it's fair," he said.

But the union remained on the warpath Wednesday.

"We have filed the ULP (unfair labor practices claim) to ensure reasonable and fair rules govern promotions," said Max Zarzana, president of the GAA, "and that an evenhanded and transparent process for investigating and adjudicating possible discipline claims remains in place."

Contact Tracey Kaplan at 408-278-3482. Follow her at Twitter.com/tkaplanreport.