Stop escaping of HTML characters in CSS in the style property?

[Andrew Robinson]

If I set a style to:

filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(
src='servlet?param1=a&param2=b');, sizingMethod='image');

becomes:

filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(
src='servlet?param1=a&param2=b');, sizingMethod='image');

The & should not be escaped as & as that is an invalid URL.

Is there a way to stop this?