If the Opposition Division considers that the European patent cannot be maintained in an unamended form, it must inform the proprietor of the patent accordingly, stating the grounds, and in appropriate cases invite him "to file, where necessary, the description, claims and drawings in amended form." As regards the time limit here, see E-VII, 1.2. Where necessary, the description adjusted in line with the new claims should also deal with the state of the art as set out in the opposition proceedings, the technical purpose and the advantages of the invention as it will then stand.
Rule 81(2) and Rule 81(3)
Proposals for amendment filed at a late stage in the proceedings may be disregarded (see T 406/86).
For amended documents, see H-III, 2.
Rule 81(2) and Rule 81(3)