Index: translate/storage/cpo.py
===================================================================
--- translate/storage/cpo.py	(revision 8228)
+++ translate/storage/cpo.py	(working copy)
@@ -505,6 +505,10 @@
                 line = -1
             gpo.po_message_add_filepos(self._gpo_message, file, line)
 
+    def setcontext(self, context):
+        """Sets the context message"""
+        gpo.po_message_set_msgctxt(self._gpo_message, context)
+
     def getcontext(self):
         msgctxt = gpo.po_message_msgctxt(self._gpo_message)
         msgidcomment = self._extract_msgidcomments()
Index: translate/storage/pypo.py
===================================================================
--- translate/storage/pypo.py	(revision 8228)
+++ translate/storage/pypo.py	(working copy)
@@ -740,6 +740,10 @@
         """Get the message context."""
         return unquotefrompo(self.msgctxt) + self._extract_msgidcomments()
 
+    def setcontext(self, context):
+        """Sets the message context"""
+        self.msgctxt = quoteforpo(context)
+
     def getid(self):
         """Returns a unique identifier for this unit."""
         context = self.getcontext()
Index: translate/storage/base.py
===================================================================
--- translate/storage/base.py	(revision 8228)
+++ translate/storage/base.py	(working copy)
@@ -159,6 +159,10 @@
     def getcontext(self):
         """Get the message context."""
         return ""
+
+    def setcontext(self, context):
+        """Sets the message context"""
+        pass
     
     def getnotes(self, origin=None):
         """Returns all notes about this unit.
Index: translate/storage/test_po.py
===================================================================
--- translate/storage/test_po.py	(revision 8228)
+++ translate/storage/test_po.py	(working copy)
@@ -130,6 +130,16 @@
         unit.source = u"Goeiemôre"
         assert not unit.isheader()
 
+    def test_context(self):
+        unit = self.UnitClass("Message")
+        assert unit.getcontext() == u""
+
+        unit.setcontext("context message")
+        assert unit.getcontext() == u"context message"
+
+        unit.setcontext("")
+        assert unit.getcontext() == u""
+
 class TestPOFile(test_base.TestTranslationStore):
     StoreClass = po.pofile
     def poparse(self, posource):