Cisco ASA LDAP Authentication and Default Group Policy

Hi, I'm running an ASA 5510 with 8.4(3) code. My remote access tunnel-group is authenticating to an Active Directory ldap server with an attribute map to assign group policy. What I would like to accomplish is that if the user is not a member of any of the groups in the attribute map, the client will disconnect or not connect at all. Is this possible?

As it presently stands, the ldap authentication mechanism will connect the client as long as the username/password are valid, and if the user is not a member of any of the groups in the attribute map, they are assigned to the default group policy.

Relevant config portions below, thanks.

tunnel-group vpn_group type remote-access
tunnel-group vpn_group general-attributes
 authentication-server-group ActiveDirectory LOCAL
tunnel-group vpn_group webvpn-attributes
 group-alias xxxxxx enable
tunnel-group vpn_group ipsec-attributes
 ikev1 pre-shared-key *****

aaa-server ActiveDirectory protocol ldap
aaa-server ActiveDirectory (inside) host 192.168.183.65
 ldap-base-dn DC=xxxxxx,DC=net
 ldap-scope subtree
 ldap-naming-attribute sAMAccountName
 ldap-login-password *****
 ldap-login-dn CN=Administrator,CN=Users,DC=xxxxxx,DC=net
 server-type microsoft
 ldap-attribute-map ldap-map
aaa-server ActiveDirectory (inside) host 192.168.183.64
 ldap-base-dn DC=xxxxxx,DC=net
 ldap-scope subtree
 ldap-naming-attribute sAMAccountName
 ldap-login-password *****
 ldap-login-dn CN=Administrator,CN=Users,DC=xxxxxx,DC=net
 server-type microsoft
 ldap-attribute-map ldap-map
 
ldap attribute-map ldap-map
  map-name  memberOf IETF-Radius-Class
  map-value memberOf "CN=xxxxxx VPN Admin,OU=Groups,DC=xxxxxx,DC=net" admin_policy
  map-value memberOf "CN=xxxxxx VPN Dial-in Global,OU=Groups,DC=xxxxxx,DC=net" employee_policy
  map-value memberOf "CN=xxxxxx VPN xxxxxx,OU=Groups,DC=xxxxxx,DC=net" xxxxxx_policy
  map-value memberOf "CN=xxxxxx VPN xxxxxx,OU=Groups,DC=xxxxxx,DC=net" xxxxxx_policy
  map-value memberOf "CN=xxxxxx VPN xxxxxx,OU=Groups,DC=xxxxxx,DC=net" xxxxxx_policy
 
group-policy DfltGrpPolicy attributes
 wins-server value 192.168.183.16 192.168.183.65
 dns-server value 192.168.183.16 192.168.183.65
 vpn-tunnel-protocol ikev1 l2tp-ipsec ssl-client ssl-clientless
 default-domain value xxxxxx.net
 address-pools value vpnpool
 webvpn
  anyconnect profiles value AdminProfile type user