The board that oversees Virginia’s juvenile correctional facilities has agreed to ban discrimination based on sexual orientation despite being counseled against such action by Attorney General Ken Cuccinelli II.

In a unanimous vote Wednesday, three members of the Board of Juvenile Justice, all of them appointed by former Democratic governor Timothy M. Kaine, backed the ban, rejecting Cuccinelli’s contention that only the General Assembly can designate a special class of citizens.

It was unclear exactly what the implications of the ban would be for Virginia’s five juvenile corrections facilities and for the more than 800 young people housed in the institutions.

But the vote marked another instance where Cuccinelli’s office has become involved in an agency or board policy decision on discrimination.

“It’s not unexpected,’’ Justin Wilson, a member of the juvenile justice board, said in an interview. “To me, it’s kind of silly to pick a social battle when we’re trying to run state facilities.”

Equality Virginia, a gay rights group, touted a national study Wednesday estimating that 8 percent of boys and 23 percent of girls in juvenile detention identify their sexuality as other than heterosexual.

The Department of Juvenile Justice operates the five facilities as well as a diagnostic facility, and the Board of Juvenile Justice sets broad policy for the agency.

At its meeting, the board said little about how the ban would affect operations in the facilities. The board did agree to obtain further advice from its staff and from the attorney general’s office on what would happen if it proceeded with the regulations.

“It is an important matter to the board and given a lot of thought to,’’ board chairwoman Barbara Myers said. “We need to follow the law.”

A spokesman for Gov. Robert McDonnell (R) said the governor did not offer any input on the regulations except to recommend that the board consult the attorney general’s office. But Wilson said the administration did object to the ban, and the head of Equality Virginia faulted both the governor and the attorney general.

James Parrish, Equality Virginia’s executive director, said Cuccinelli (R) and McDonnell “appear, once again, to have put their brand of perceived political correctness above the safety of our children.” 

“Our children need and deserve protection against discrimination and harassment, especially when they are held in state custody with no avenue of escape or safe harbor from abuse,” he said.

In at least three other instances since McDonnell and Cuccinelli were sworn into office last year, state agencies have had to weigh protections based on sexual orientation against advice from the state’s top elected officials.

In April, the State Board of Social Services accepted the advice of Cuccinelli and the McDonnell administration and overwhelmingly voted to continue a practice that some argue allows faith-based organizations in Virginia to discriminate in adoptions.

But earlier, the state’s public colleges appeared to reject Cuccinelli’s counsel that they rescind policies that ban discrimination on the basis of sexual orientation.

Last year, the Board of Corrections reaffirmed a policy prohibiting discrimination on the basis of sexual orientation, overruling concerns expressed by a representative from Cuccinelli’s office.

The juvenile justice board began a massive rewrite of its 300-page regulations in 2009 during the Kaine administration. After public input, members say, they decided to include sexual orientation as a protected status.

Jeff Caldwell, a spokesman for McDonnell, said “the governor expects boards and agencies to promulgate regulations consistent with the established laws and public policies of the commonwealth,’’ Caldwell said. “The DJJ board made this decision based upon advice from the Office of the Attorney General that making the proposed change to existing regulations would exceed their statutory authority.”

Cuccinelli spokesman Brian Gottstein declined to comment.

The seven-member board is made up of all Kaine appointees except for one member appointed by McDonnell last year. Three members were absent Wednesday, and chairwoman Barbara Myers abstained.

Myers declined to comment on why she did not vote. The other two board members, Kahan S. Dhillon Jr. and Aida L. Pacheco, did not return phone calls.

Staff writer Rosalind S. Helderman and researcher Magda Jean-Louis contributed to this report.