The Department of Labor's new Retirement Security Rule is facing its first legal challenge just days after it was finalized April 23. Industry observers expect it to be the first of several lawsuits to challenge the rule set to go into effect Sept. 23.

In a lawsuit filed in the U.S. District Court for the Eastern District of Texas, plaintiffs said the department exceeded its authority in crafting the rule and asked the court to vacate the rule under the Administrative Procedures Act on the grounds it is contrary to law as well as arbitrary and capricious. The lawsuit calls the rule an "assault on insurance agents selling annuities," and said it reflects deep-rooted misunderstandings and bias on the part of the DOL against annuities and the insurance sales channel through which they are sold.

Plaintiffs include the Federation of Americans for Consumer Choice Inc., a trade organization whose members are independent marketing organizations, insurance agents and agencies that market fixed insurance products including annuities.