diff --git a/frontend/src/api/tests.ts b/frontend/src/api/tests.ts
index 0c789a5..5f12da4 100644
--- a/frontend/src/api/tests.ts
+++ b/frontend/src/api/tests.ts
@@ -248,6 +248,19 @@ export async function validateAsBlueLead(
   return data;
 }
 
+// ── Dispute resolution ───────────────────────────────────────────────
+
+export interface ResolveDisputePayload {
+  target_team: "red" | "blue";
+  notes?: string;
+}
+
+/** The approving lead flips to reject, choosing which team must redo the work. */
+export async function resolveDispute(testId: string, payload: ResolveDisputePayload): Promise<Test> {
+  const { data } = await client.post<Test>(`/tests/${testId}/resolve-dispute`, payload);
+  return data;
+}
+
 // ── Reopen ─────────────────────────────────────────────────────────
 
 /** Reopen a rejected test — moves back to draft. */
diff --git a/frontend/src/components/test-detail/ResolveDisputeModal.tsx b/frontend/src/components/test-detail/ResolveDisputeModal.tsx
new file mode 100644
index 0000000..c279b90
--- /dev/null
+++ b/frontend/src/components/test-detail/ResolveDisputeModal.tsx
@@ -0,0 +1,112 @@
+import { useState } from "react";
+import { Shield, ShieldCheck, Loader2, X, XCircle } from "lucide-react";
+
+// ── Props ──────────────────────────────────────────────────────────
+
+interface ResolveDisputeModalProps {
+  isSubmitting: boolean;
+  onSubmit: (targetTeam: "red" | "blue", notes: string) => void;
+  onClose: () => void;
+}
+
+// ── Component ──────────────────────────────────────────────────────
+
+export default function ResolveDisputeModal({
+  isSubmitting,
+  onSubmit,
+  onClose,
+}: ResolveDisputeModalProps) {
+  const [targetTeam, setTargetTeam] = useState<"red" | "blue" | null>(null);
+  const [notes, setNotes] = useState("");
+
+  const canSubmit = targetTeam !== null && !isSubmitting;
+
+  return (
+    <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/50 backdrop-blur-sm">
+      <div className="w-full max-w-lg rounded-xl border border-gray-800 bg-gray-900 shadow-xl">
+        {/* Header */}
+        <div className="flex items-center justify-between border-b border-gray-800 px-6 py-4">
+          <div className="flex items-center gap-2">
+            <XCircle className="h-5 w-5 text-red-400" />
+            <h3 className="text-lg font-semibold text-white">Change Vote to Rejected</h3>
+          </div>
+          <button
+            onClick={onClose}
+            className="rounded p-1 text-gray-400 hover:bg-gray-800 hover:text-white"
+          >
+            <X className="h-5 w-5" />
+          </button>
+        </div>
+
+        {/* Body */}
+        <div className="space-y-5 px-6 py-5">
+          <p className="text-sm text-gray-400">
+            You're agreeing that this test needs rework. Instead of restarting from scratch,
+            pick which team's work is actually the problem — the test goes straight back to
+            their queue and the other team's work is left untouched.
+          </p>
+
+          <div>
+            <h4 className="mb-2 text-sm font-medium text-gray-300">Send back to</h4>
+            <div className="flex gap-3">
+              <button
+                onClick={() => setTargetTeam("red")}
+                className={`flex flex-1 items-center justify-center gap-2 rounded-lg border p-3 text-sm font-medium transition-colors ${
+                  targetTeam === "red"
+                    ? "border-orange-500 bg-orange-500/10 text-orange-400"
+                    : "border-gray-700 bg-gray-800 text-gray-400 hover:border-gray-600"
+                }`}
+              >
+                <Shield className="h-4 w-4" />
+                Red Team Queue
+              </button>
+              <button
+                onClick={() => setTargetTeam("blue")}
+                className={`flex flex-1 items-center justify-center gap-2 rounded-lg border p-3 text-sm font-medium transition-colors ${
+                  targetTeam === "blue"
+                    ? "border-indigo-500 bg-indigo-500/10 text-indigo-400"
+                    : "border-gray-700 bg-gray-800 text-gray-400 hover:border-gray-600"
+                }`}
+              >
+                <ShieldCheck className="h-4 w-4" />
+                Blue Team Queue
+              </button>
+            </div>
+          </div>
+
+          <div>
+            <label className="mb-1.5 block text-sm font-medium text-gray-300">
+              Notes (optional)
+            </label>
+            <textarea
+              value={notes}
+              onChange={(e) => setNotes(e.target.value)}
+              rows={3}
+              className="w-full rounded-lg border border-gray-700 bg-gray-800 px-3 py-2 text-sm text-gray-200 placeholder-gray-500 focus:border-red-500 focus:outline-none focus:ring-1 focus:ring-red-500"
+              placeholder="What needs to be fixed..."
+            />
+          </div>
+        </div>
+
+        {/* Footer */}
+        <div className="flex justify-end gap-3 border-t border-gray-800 px-6 py-4">
+          <button
+            onClick={onClose}
+            disabled={isSubmitting}
+            className="rounded-lg border border-gray-700 px-4 py-2 text-sm text-gray-400 hover:bg-gray-800 disabled:opacity-50"
+          >
+            Cancel
+          </button>
+          <button
+            onClick={() => targetTeam && onSubmit(targetTeam, notes)}
+            disabled={!canSubmit}
+            className="flex items-center gap-1.5 rounded-lg bg-red-600 px-4 py-2 text-sm font-medium text-white hover:bg-red-500 disabled:opacity-50 transition-colors"
+          >
+            {isSubmitting && <Loader2 className="h-4 w-4 animate-spin" />}
+            Confirm Rejection
+          </button>
+        </div>
+      </div>
+    </div>
+  );
+}
diff --git a/frontend/src/components/test-detail/TestDetailHeader.tsx b/frontend/src/components/test-detail/TestDetailHeader.tsx
index 1c7a52c..81d701f 100644
--- a/frontend/src/components/test-detail/TestDetailHeader.tsx
+++ b/frontend/src/components/test-detail/TestDetailHeader.tsx
@@ -79,6 +79,7 @@ interface TestDetailHeaderProps {
   onStartBlueWork: () => void;
   onOpenValidateModal: (side: "red" | "blue") => void;
   onOpenReviewModal: (side: "red" | "blue") => void;
+  onOpenResolveDisputeModal: () => void;
   onReopen: () => void;
   onPauseTimer: () => void;
   onResumeTimer: () => void;
@@ -100,6 +101,7 @@ export default function TestDetailHeader({
   onStartBlueWork,
   onOpenValidateModal,
   onOpenReviewModal,
+  onOpenResolveDisputeModal,
   onReopen,
   onPauseTimer,
   onResumeTimer,
@@ -329,8 +331,6 @@ export default function TestDetailHeader({
         (role === "blue_lead" && test.blue_validation_status === "rejected") ||
         (role === "admin" && test.blue_validation_status === "rejected");
 
-      const approvingSide: "red" | "blue" =
-        test.red_validation_status === "approved" ? "red" : "blue";
       const rejectingSide: "red" | "blue" =
         test.red_validation_status === "rejected" ? "red" : "blue";
 
@@ -353,9 +353,9 @@ export default function TestDetailHeader({
                   Request Discussion
                 </button>
               )}
-              {/* Change approving vote to rejected */}
+              {/* Change approving vote to rejected — routes to the team at fault */}
               <button
-                onClick={() => onOpenValidateModal(approvingSide)}
+                onClick={onOpenResolveDisputeModal}
                 className="flex items-center gap-1.5 rounded-lg bg-red-700/80 px-4 py-2 text-sm font-medium text-white hover:bg-red-600 transition-colors"
               >
                 <XCircle className="h-4 w-4" />
diff --git a/frontend/src/pages/TestDetailPage.tsx b/frontend/src/pages/TestDetailPage.tsx
index 7d66ea4..33f1fa2 100644
--- a/frontend/src/pages/TestDetailPage.tsx
+++ b/frontend/src/pages/TestDetailPage.tsx
@@ -16,6 +16,7 @@ import {
   validateAsBlueLead,
   reviewAsRedLead,
   reviewAsBlueLead,
+  resolveDispute,
   reopenTest,
   pauseTimer,
   resumeTimer,
@@ -32,6 +33,7 @@ import TestDetailHeader from "../components/test-detail/TestDetailHeader";
 import TeamTabs from "../components/test-detail/TeamTabs";
 import ValidationModal from "../components/test-detail/ValidationModal";
 import ReviewModal from "../components/test-detail/ReviewModal";
+import ResolveDisputeModal from "../components/test-detail/ResolveDisputeModal";
 import ConfirmDialog from "../components/ConfirmDialog";
 import JiraLinkPanel from "../components/JiraLinkPanel";
 import TestPhaseTimeline from "../components/TestPhaseTimeline";
@@ -64,6 +66,8 @@ export default function TestDetailPage() {
     side: "red" | "blue";
   }>({ open: false, side: "red" });
 
+  const [resolveDisputeModalOpen, setResolveDisputeModalOpen] = useState(false);
+
   const [confirmReopen, setConfirmReopen] = useState(false);
   const [holdModal, setHoldModal] = useState(false);
   const [holdReason, setHoldReason] = useState("");
@@ -284,6 +288,17 @@ export default function TestDetailPage() {
     onError: (err: unknown) => showToast(extractError(err), "error"),
   });
 
+  const resolveDisputeMutation = useMutation({
+    mutationFn: (payload: { target_team: "red" | "blue"; notes?: string }) =>
+      resolveDispute(testId!, payload),
+    onSuccess: () => {
+      invalidateAll();
+      setResolveDisputeModalOpen(false);
+      showToast("Dispute resolved — test sent back for rework", "success");
+    },
+    onError: (err: unknown) => showToast(extractError(err), "error"),
+  });
+
   const reopenMutation = useMutation({
     mutationFn: () => reopenTest(testId!),
     onSuccess: () => {
@@ -406,6 +421,10 @@ export default function TestDetailPage() {
     });
   };
 
+  const handleResolveDisputeSubmit = (targetTeam: "red" | "blue", notes: string) => {
+    resolveDisputeMutation.mutate({ target_team: targetTeam, notes: notes || undefined });
+  };
+
   const isTransitioning =
     startExecMutation.isPending ||
     submitRedMutation.isPending ||
@@ -486,6 +505,7 @@ export default function TestDetailPage() {
         onStartBlueWork={() => startBlueWorkMutation.mutate()}
         onOpenValidateModal={(side) => setValidationModal({ open: true, side })}
         onOpenReviewModal={(side) => setReviewModal({ open: true, side })}
+        onOpenResolveDisputeModal={() => setResolveDisputeModalOpen(true)}
         onReopen={() => setConfirmReopen(true)}
         onPauseTimer={() => pauseTimerMutation.mutate()}
         onResumeTimer={() => resumeTimerMutation.mutate()}
@@ -780,6 +800,15 @@ export default function TestDetailPage() {
         />
       )}
 
+      {/* Resolve Dispute Modal (approver flips vote to reject, picks a queue) */}
+      {resolveDisputeModalOpen && (
+        <ResolveDisputeModal
+          isSubmitting={resolveDisputeMutation.isPending}
+          onSubmit={handleResolveDisputeSubmit}
+          onClose={() => setResolveDisputeModalOpen(false)}
+        />
+      )}
+
       {/* Save as Template Modal */}
       {showTemplateModal && (
         <SaveAsTemplateModal