An objection of lack of unity of invention, if applicable, should already have been raised at the search stage. If such an objection was not raised, but the examining division nevertheless considers that the requirements of Art. 82 EPC are not met, the question of lack of unity will be addressed as early as possible during examination (Guidelines C-III, 3).
New R. 137(5) EPC (OJ 2009, 299) (former R. 137(4) EPC - as in force from 13 December 2007 until 31 March 2010; R. 86 (4) EPC 1973) relates to amendments made during the grant procedure which are under the control of the examining division. It stipulates that amended claims may not relate to unsearched subject-matter which does not combine with the originally claimed invention or group of inventions to form a single general inventive concept. Nor may they relate to subject-matter not searched in accordance with R. 62a or R. 63 EPC.