Blank spaces Calc to xml

I am using an .xsl file as an export filter to convert an Open Office Calc file to xml. One of the fields is the DNI, which in the calc is like D (two blank spaces) XXXXXXXXX. The problem is that when exporting to xml the two blanks become one. Here is the filter code xsl:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:office="urn:oasis:names:tc:opendocument:xmlns:office:1.0" xmlns:table="urn:oasis:names:tc:opendocument:xmlns:table:1.0" xmlns:text="urn:oasis:names:tc:opendocument:xmlns:text:1.0" exclude-result-prefixes="office table text">

<xsl:preserve-space elements="*" />

<xsl:template match="/">
 <root>
  <xsl:apply-templates select="/*/office:body" />
 </root>
</xsl:template>

<xsl:template match="office:body">
 <xsl:apply-templates />
</xsl:template>

<xsl:template match="office:spreadsheet">
 <xsl:apply-templates />
</xsl:template>

<xsl:template match="office:spreadsheet/table:table">

<xsl:for-each select="table:table-row[position() &gt; 1]">
 <CIUDADANO><xsl:text>
</xsl:text>
<NIF_NIE>
<xsl:choose>
      <xsl:when test="substring(table:table-cell[1]/text:p,3,1)='X' or substring(table:table-cell[1]/text:p,3,1)='Y'">
           <xsl:value-of select="replace(table:table-cell[1]/text:p, concat('(^.*?)', 'D'),concat('$1','E'))" />
      </xsl:when>
      <xsl:otherwise>
           <xsl:value-of select="table:table-cell[1]/text:p"/>
      </xsl:otherwise>
 </xsl:choose>
 </NIF_NIE><xsl:text>
</xsl:text>
 <UNIDADES_DE_COMPETENCIA><xsl:text>
 </xsl:text>
  <UNIDAD><xsl:text>
  </xsl:text>
        <CODIGO><xsl:value-of select="table:table-cell[2]/text:p" /></CODIGO><xsl:text>
</xsl:text>
    </UNIDAD><xsl:text>
</xsl:text>
 </UNIDADES_DE_COMPETENCIA><xsl:text>
</xsl:text>
 </CIUDADANO><xsl:text>
 </xsl:text>

</xsl:for-each>

</xsl:template>
</xsl:stylesheet>