The Florida Department of Environmental Protection (“DEP”) appeals the district court’s order overruling its objection to court-ordered mediation with the vessel owners who filed these consolidated limitation actions. The district court either declined to rule or deferred ruling on various motions in which DEP argued it was entitled to Eleventh Amendment immunity, and ordered DEP to mediate. We conclude that the district court erred in ordering DEP to mediate without first addressing the Eleventh Amendment issue.
On August 10, 1995, two tug-barge flotillas and a freighter were involved in a collision near Tampa Bay, resulting in the spill of petroleum products into Florida’s navigable waters.
DEP filed answers and affirmative claims for relief under the Oil Pollution Act of 1990, 33 U.S.C. §§ 2701 to 2761 (1994), and the Pollutant Spill Prevention and Control Act, Fla.Stat.Ann. §§ 376.011 to 376.21 (West 1988), in all three limitation actions. Bou-chard and Maritrans filed counterclaims against DEP. DEP then moved to dismiss the Bouchard and Maritrans limitation actions and counterclaims, arguing that the Eleventh Amendment prevents the vessel owners from haling DEP into federal court.
Without ruling on DEP’s motions to dismiss, the district court consolidated the three limitation actions and ordered the parties to participate in mediation for two months. DEP filed motions in all three limitation actions objecting to the court-ordered mediation on Eleventh Amendment grounds. The district court overruled DEP’s objections, noting that the vessel owners appeared eager to settle the claims against them, and holding that the court had inherent power to order mediation. DEP filed this appeal from the district court’s order overruling its objections to mediation.
II. Jurisdiction
The vessel owners moved to dismiss this appeal for lack of jurisdiction. A motions panel of this court held that the district court’s order compelling DEP to participate in mediation was immediately appealable, and we agree. See 11th Cir.R. 27 — 1(f) (ruling of a motions panel is not binding on panel to which case is assigned for disposition on merits). DEP argues that we have jurisdiction over this appeal because the district court’s order rejected its assertion of Eleventh Amendment immunity. See Puerto Rico Aqueduct and Sewer Auth. v. Metcalf & Eddy, Inc.,
Even though the district court deferred a ruling on Eleventh Amendment immunity, we have jurisdiction to review the court’s order directing DEP to mediate. See Collins v. School Bd. of Dade County,
III. Discussion
As we have noted, the district court did not address whether DEP was entitled to Eleventh Amendment immunity in the mediation order, and we decline to exercise our discretion to address this issue for the first time on appeal. See Lordmann Enterprises, Inc. v. Equicor, Inc.,
The nature and purposes of Eleventh Amendment immunity suggest that it is a threshold issue. While the Supreme Court has held that the Eleventh Amendment is not jurisdictional in the sense that courts must address the issue sua sponte, Patsy v. Board of Regents,
We hold that where, as here, the Eleventh Amendment question presented is a purely legal one, the district court abuses its discretion by reserving a ruling on immunity and ordering the parties to mediate.
We vacate the district court’s order overruling DEP’s objections to mediation, and remand for further proceedings consistent with this opinion.
VACATED and REMANDED.
Notes
. The parties dispute whether there was contact between all three vessels, and whether there were actually two collisions.
. In its motions to dismiss, DEP also requested permission to withdraw its claims against Bou-chard and Maritrans.
. In its initial brief, DEP took the position that the district court ruled on and denied Eleventh Amendment immunity in the mediation order, and it is a close question whether DEP’s initial brief raises the argument that the district court erred by reserving a ruling on its Eleventh Amendment immunity defense. Generally, issues not discussed in a party’s initial brief are deemed waived, but we construe briefs liberally in determining the issues raised on appeal. Allstate Ins. Co. v. Swann,
. Tsacaba also argues that the district court did not err in ordering DEP to mediate in the Tsaca-ba limitation action because DEP did not move to dismiss that case on Eleventh Amendment grounds. But DEP filed objections to mediation on Eleventh Amendment grounds in all three limitation actions, thus adequately raising the issue in the district court.
. The district court cited In re Novak,
.Neither parly has suggested that discovery is needed before the Eleventh Amendment issue in this case is addressed. We have no occasion to consider whether the district court may enter other preliminary orders, including orders relating to discovery, before ruling on a claim of Eleventh Amendment immunity.
