Let's urlunqoute the filter

src/representatives/filters.py

@@ -4,6 +4,7 @@ from datetime import datetime
 from rest_framework.filters import BaseFilterBackend
 from django.db.models import Q
 from django.conf import settings
+from django.utils.http import urlunquote
 
 
 from .models import Mandate
@@ -49,7 +50,7 @@ class ActiveConstituencyFilterBackend(BaseFilterBackend):
 
         if self.query_param in request.GET:
             if len(request.GET[self.query_params]):
-                mandates = request.GET[self.query_param].split(',')
+                mandates = urlunqoute(request.GET[self.query_param]).split(',')
                 qs = qs.filter(mandates__in=Mandate.objects.filter(
                     Q(end_date__gte=datetime.today) |
                     Q(end_date__isnull=True)).filter(