RALEIGH, N.C. >> Former “American Idol” runner-up Clay Aiken held a slight edge over textile entrepreneur Keith Crisco in a congressional primary election Wednesday, with officials working to count every last ballot before declaring a winner.

There were less than 400 votes separating the Democratic Party candidates in the Republican-leaning 2nd Congressional District. The winner faces Republican incumbent Renee Ellmers — who was first elected in the tea party wave of 2010 — in November.

Both Aiken and Crisco, once the state’s top business recruiter under Gov. Beverly Perdue, have cast themselves as centrists. Both will have to overcome the district’s strong bloc of evangelical Christian voters who tend to vote Republican. Aiken has said previously that he doesn’t believe the fact he is gay will affect whether people vote for him.

The state elections board on Wednesday showed the latest unofficial results giving Aiken the 40 percent of the tally that he needs to avoid a runoff election in July and a margin big enough that Crisco can’t request a recount.

Aiken was carefully watching the numbers, spokeswoman Tucker Middleton said.

“It’s close, but we’re confident,” she said.

But almost 400 absentee ballots issued had not been returned, according to data provided Wednesday by the state elections board. Absentee ballots and provisional ballots — those cast by voters who may not be properly registered — won’t be tallied until Tuesday, state elections board spokesman Josh Lawson said.

It was not yet clear how many provisional ballots were pending a decision on whether they were properly cast, he said.

Crisco planned to wait until at least Thursday to consider a next step, spokesman Aaron Fiedler said in an email.

“This election is still very tight,” Crisco said in a statement.