2.1.10 [SVG1.1:2011] Section 10.15, White space handling
The specification states (see also [SVG1.1:2011] Section 5.10., The xml:lang and xml:space attributes):
SVG supports the standard XML attribute xml:space to specify the handling of white space characters within a given 'text' element's character data. The SVG user agent has special processing rules associated with this attribute as described below. These are behaviors that occur subsequent to XML parsing and any construction of a Document Object Model.
IE9 Mode, IE10 Mode, IE11 Mode, and EdgeHTML Mode (All Versions)
The xml:space attribute is not supported.