The American Federation of State, County and Municipal Workers, which played a key role in helping elect Mayor Vincent C. Gray last year, announced today that it is supporting former council member Vincent B. Orange in the April 26 election for an at-large seat on the council.

“After interviewing Vincent Orange, we have concluded that he has the experience, integrity and accountability that are needed in the representation of city workers and the District of Columbia,” said Geo T. Johnson, executive director of AFSCME Council 20.

With 8,000 members in the Washington region, AFSCME’s endorsement signals a split among major labor unions in this year’s special election. Last year, nearly all the major labor unions were supporting Gray (D) in his matchup against former mayor Adrian M. Fenty (D).

Earlier in the week, the Service Employees International Union announced that it was supporting incumbent Sekou Biddle (D) in the at-large race. The hotel workers union is also supporting Biddle.

The April 26 special election, which will include school board races in Wards 4 and 8, is expected to draw a small percentage of registered voters to the polls. The low-turnout race could set up a grudge match between unions over who can best organize and mobilize support for favored candidates.