(CNN) One of the Department of Justice attorneys who withdrew from an ongoing case over the Affordable Care Act just before the government said it would no longer defend the law has resigned.

Joel McElvain is one of three career Justice Department attorneys who withdrew from the lawsuit brought by Texas and a coalition of other Republican-led states challenging the constitutionality of the Affordable Care Act. He has tendered his resignation and his last day will be July 6, according to a department spokesperson.

The two other employees who withdrew from the case -- Rebecca Kopplin and Eric Beckenhauer -- have had no change in their employment status, the spokesperson said.

The Washington Post was the first to report McElvain's resignation, which is said to come after "internal frustration generated by the decision, according to people familiar with the matter."

McElvain did not immediately respond to a request for comment.

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