SVG Foreign Object not displaying with SVG Namespace - svg

Question

I have the following SVG file.
<?xml version="1.0" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN"
"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<!--<svg width="100%" height="500">-->
<svg id="deviceImage" class="DeviceImage" version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" preserveAspectRatio="xMinYMin" currentScale="1" width="3000px" height="1500px" oncontextmenu="return false">
<script type="text/ecmascript">
<![CDATA[
function ExmpleFunction(event, componentGroup)
{
alert('Hello World');
}
]]>
</script>
<defs>
<!-->>>TestShape>>>-->
<symbol id="TestShape">
<polygon points="1,1 650,1 630,175 21,175"></polygon>
</symbol>
<!--<<<TestShape<<<-->
</defs>
<!--TestShape-->
<g id="p1" transform="translate(50, 35)" visibility="visible">
<use id="p2Basic" xlink:href = "#TestShape"/>
</g>
<rect x="500" y="10" width="100" height="150" fill="blue"/>
<foreignObject x="0" y="0" width="200" height="250">
<div xmlns="http://www.w3.org/1999/xhtml">
<embed id="wert" src="TestModule-Basic.svg" type="image/svg+xml" />
</div>
</foreignObject>
</svg>
The aim is to embed another svg image which supports the internal script (so this can't be done as an image) so I am using foreignObject
When run the above code displays the test shape and the rectangle, but it does not display the svg image in the foreignObject.
By experimenting I discovered that if I remove the xmlns="http://www.w3.org/2000/svg" from the main SVG node, the svg image in the foreignObject is displayed but the test shape and rectangle are not displayed. I also see the text within the script tag as part of the image.
I obviously need to include the svg namespace but I am not sure how I get both to display?
All help appreciated!