SOAPpy namespace problem

Experts,
I am attempting to use SOAPpy to send SOAP messages.  Here is a sample of what I'm executing:
from SOAPpy import SOAPProxy

url = 'http://192.168.10.128:8080/ws/SessionLogin?wsdl'

# define the namespace
namespace = 'http://whatever.org'
server = SOAPProxy(url)

print server._ns(namespace).login(String_1 = "<TSSLogin Username='username' Password='password' \>")


Which results in the following string being sent:
<?xml version="1.0" encoding="UTF-8"?>
<SOAP-ENV:Envelope
  SOAP-ENV:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"
  xmlns:SOAP-ENC="http://schemas.xmlsoap.org/soap/encoding/"
  xmlns:xsi="http://www.w3.org/1999/XMLSchema-instance"
  xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/"
  xmlns:xsd="http://www.w3.org/1999/XMLSchema"
>
<SOAP-ENV:Body>
<ns1:login xmlns:ns1="http://www.tamalesoftware.com/ws/SessionLogin" SOAP-ENC:ro
ot="1">
<String_1 xsi:type="xsd:string">&lt;TSSLogin Username="admin" Password="admin" /
&gt;</String_1>
</ns1:login>
</SOAP-ENV:Body>
</SOAP-ENV:Envelope>


I need the String_1 element to read <ns1:String_1
meaning with the namespace...
How do I accomplish that?

Thanks.
Asim