It is possible to apply to have a patent revoked after its registration.
The grounds on which a patent may be revoked are set out in Section 72 of the Patents Act 1977 and the corresponding Article of the EPC.
These state that a patent may be revoked if;
i) the invention is not a patentable invention
ii) the patent was granted to a person who was not entitled to that patent;
iii) the specification of the patent does not disclose the invention clearly enough and completely enough for it to be performed by a person skilled in the art;
iv) the material in the patent extends beyond the material in the application as filed.
It is set in law that any person can apply to have a patent revoked regardless of whether or not they hold an interest in that patent being revoked.
The availability of patent revocation action means that it is vital that before a patent application is filed it is important to have a thorough search conducted and that the patent is drafted by professional.