ansible xml module - set namespace & namespaced elements

I need to change the following xml

<network>
  <name>docker-machines</name>
  <uuid>ea91ff7c-aa2b-4fa9-b59d-d1fae70285ad</uuid>
  ...
</network>

to

<network xmlns:dnsmasq='http://libvirt.org/schemas/network/dnsmasq/1.0'>
  <name>docker-machines</name>
  <uuid>ea91ff7c-aa2b-4fa9-b59d-d1fae70285ad</uuid>
  ...
  <dns>
    <forwarder addr='5.1.66.255'/>
  </dns>
  <dnsmasq:options>
    <dnsmasq:option value='dhcp-option=option:ntp-server,10.10.14.1'/>
  </dnsmasq:options>
</network>

I have successfully managed to set the <dns><forwarder> elemnent using this:

- name: Set resolver for docker-machines network
  xml:
    path: /etc/libvirt/qemu/networks/docker-machines.xml
    xpath: /network/dns
    set_children:
      - forwarder:
          addr: 8.8.8.8

Unfortunately, creating the namespaced elements does not seem to be that easy. For example, I have tried this:

- name: Set ntp server for docker-machines network dhcp
  xml:
    path: /etc/libvirt/qemu/networks/docker-machines.xml
    xpath: /network/dnsmasq:options/dnsmasq:option
    namespaces:
      dnsmasq: http://libvirt.org/schemas/network/dnsmasq/1.0
    attribute: value
    value: "dhcp-option=option:ntp-server,10.10.14.1"

...but it does the correctly set the namespace on <network> and instead creates weird <ns0:> elements.

How can I do this correctly?