diff --git a/openslides/participant/forms.py b/openslides/participant/forms.py
index bab9ba92c..bd50ac5a9 100644
--- a/openslides/participant/forms.py
+++ b/openslides/participant/forms.py
@@ -11,13 +11,13 @@
 """
 
 from django import forms
+from django.contrib import messages
 from django.contrib.auth.models import Permission
-from django.utils.translation import ugettext_lazy as _  # TODO: Change this in the code
+from django.contrib.contenttypes.models import ContentType
+from django.utils.translation import ugettext as _, ugettext_lazy
 from django.conf import settings
 
-from openslides.utils.forms import (
-    CssClassMixin, LocalizedModelMultipleChoiceField)
-
+from openslides.utils.forms import CssClassMixin, LocalizedModelMultipleChoiceField
 from openslides.participant.models import User, Group
 from openslides.participant.api import get_registered_group
 
@@ -25,7 +25,7 @@ from openslides.participant.api import get_registered_group
 class UserCreateForm(forms.ModelForm, CssClassMixin):
     groups = forms.ModelMultipleChoiceField(
         queryset=Group.objects.exclude(name__iexact='anonymous'),
-        label=_("Groups"), required=False)
+        label=ugettext_lazy('Groups'), required=False)
 
     def __init__(self, *args, **kwargs):
         if kwargs.get('instance', None) is None:
@@ -42,19 +42,42 @@ class UserCreateForm(forms.ModelForm, CssClassMixin):
 
 
 class UserUpdateForm(UserCreateForm):
+    """
+    Form to update an user. It raises a validation error, if a non-superuser
+    user edits himself and removes the last group containing the permission
+    to manage participants.
+    """
     class Meta:
         model = User
         fields = ('username', 'title', 'first_name', 'last_name', 'gender', 'email',
                   'groups', 'structure_level', 'committee', 'about_me', 'comment',
                   'is_active', 'default_password')
 
+    def __init__(self, *args, **kwargs):
+        self.request = kwargs.pop('request')
+        return super(UserUpdateForm, self).__init__(*args, **kwargs)
+
+    def clean(self, *args, **kwargs):
+        """
+        Raises a validation error, if a non-superuser user edits himself
+        and removes the last group containing the permission to manage participants.
+        """
+        if self.request.user == self.instance and not self.instance.is_superuser:
+            protected_perm = Permission.objects.get(content_type=ContentType.objects.get(app_label='participant', model='user'),
+                                                    codename='can_manage_participant')
+            if not self.cleaned_data['groups'].filter(permissions__in=[protected_perm]).exists():
+                error_msg = _('You can not remove the last group containing the permission to manage participants.')
+                messages.error(self.request, error_msg)
+                raise forms.ValidationError(error_msg)
+        return super(UserUpdateForm, self).clean(*args, **kwargs)
+
 
 class GroupForm(forms.ModelForm, CssClassMixin):
     permissions = LocalizedModelMultipleChoiceField(
-        queryset=Permission.objects.all(), label=_("Permissions"),
+        queryset=Permission.objects.all(), label=ugettext_lazy('Permissions'),
         required=False)
     users = forms.ModelMultipleChoiceField(
-        queryset=User.objects.all(), label=_("Participants"), required=False)
+        queryset=User.objects.all(), label=ugettext_lazy('Participants'), required=False)
 
     def __init__(self, *args, **kwargs):
         # Initial users
@@ -91,11 +114,11 @@ class GroupForm(forms.ModelForm, CssClassMixin):
             # Editing the anonymous-user
             if self.instance.name.lower() != data.lower():
                 raise forms.ValidationError(
-                    _('You can not edit the name for this group.'))
+                    ugettext_lazy('You can not edit the name for this group.'))
         else:
             if data.lower() in ['anonymous', 'registered']:
                 raise forms.ValidationError(
-                    _('Group name "%s" is reserved for internal use.') % data)
+                    ugettext_lazy('Group name "%s" is reserved for internal use.') % data)
         return data
 
     class Meta:
@@ -113,4 +136,4 @@ class UsersettingsForm(forms.ModelForm, CssClassMixin):
 
 class UserImportForm(forms.Form, CssClassMixin):
     csvfile = forms.FileField(widget=forms.FileInput(attrs={'size': '50'}),
-                              label=_("CSV File"))
+                              label=ugettext_lazy('CSV File'))
diff --git a/openslides/participant/views.py b/openslides/participant/views.py
index cff7d8922..4255806e8 100644
--- a/openslides/participant/views.py
+++ b/openslides/participant/views.py
@@ -116,6 +116,11 @@ class UserUpdateView(UpdateView):
     form_class = UserUpdateForm
     success_url_name = 'user_overview'
 
+    def get_form_kwargs(self, *args, **kwargs):
+        form_kwargs = super(UserUpdateView, self).get_form_kwargs(*args, **kwargs)
+        form_kwargs.update({'request': self.request})
+        return form_kwargs
+
 
 class UserDeleteView(DeleteView):
     """