A federal appeals court ruled on Thursday that the Department of Labor overstepped its authority when it wrote a rule that required financial professionals, including brokers and insurance agents, to put their customers’ financial interests ahead of their own.

The United States Court of Appeals for the Fifth Circuit overturned a lower court’s ruling in a 2-to-1 decision siding with the plaintiffs, which include several groups representing the financial services industry.

“That times have changed, the financial market has become more complex, and I.R.A. accounts have assumed enormous importance are arguments for Congress to make adjustments in the law, or for other appropriate federal or state regulators to act within their authority,” the majority wrote in their opinion. “A perceived ‘need’ does not empower D.O.L. to craft de facto statutory amendments or to act beyond its expressly defined authority.”

The strongly worded decision is not necessarily the end of the fiduciary rule, lawyers said, but its future is highly uncertain.