NZ Patent Oppositions – Why oppose?

Date: 2012-10-18
Author: Tracey Hendy

In our continuing series of articles on New Zealand patent oppositions, we look at the pros and cons of opposition versus revocation of the patent in a court.

In our earlier article NZ Patent Oppositions – when can I file?, we looked at the opportunities for third parties to oppose a patent or application before the New Zealand Patent Office.

But apart from opposition before the New Zealand Patent Office, it is possible to apply to a court to revoke a patent. This can be done as a stand-alone action. However, a revocation action is typically brought as a counterclaim to an infringement case brought by the patentee.

The question is often asked: why oppose when I can bring a revocation action if I get sued for infringement?


The first consideration is one of cost. Opposition is considered to be cheaper. The evidentiary standard required for evidence before the New Zealand Patent Office is not as high as required for court evidence. Additionally, patent oppositions typically do not involve cross examination of witnesses and are therefore swifter proceedings.

Risk of temporary injunction

Typically, a patent infringement case may take several years before the court decides and makes any appropriate orders. Such orders might include an injunction to stop infringement, damages or an account of profits.

However, the patentee is also able in certain circumstances, to apply for a temporary order (known as an interim injunction) to stop infringement pending the full trial. Given the nature of the order as a temporary measure, the case for infringement and validity is not fully considered, only whether there is a “serious question to be tried”. If that test is satisfied, the court moves on to weigh up the harm done to the defendant if the injunction is granted compared to the harm done to the plaintiff if the injunction is not granted.

So even if the defendant is aware of invalidating prior art, that might not be considered in interim injunction proceedings and the defendant may well be faced with a temporary order restraining manufacture and/or sales in New Zealand of products covered by the patent. Given the possible damage to the defendant’s business in this scenario, this puts the defendant in a less favourable position for settlement negotiations than if the defendant had taken a more aggressive approach and sought revocation at an earlier stage, for example by opposing the application.

More extensive grounds under revocation

On the other hand, revocation before a court provides more extensive grounds upon which a patent may be revoked compared to opposition proceedings.

In opposition proceedings, the ground of obviousness is recited as “obvious and clearly does not involve any inventive step” whereas the same ground under revocation does not include the word “clearly”. Thus, it must be a clear case before the Patent Office will revoke a patent for being obvious. If the features of the invention can be found in a single prior art document and the common general knowledge of those skilled in the field, then there are reasonable prospects of success under obviousness. Success is harder to achieve where all the features can only be found in a mosaic of two prior art documents. 

Consequently, it may be more difficult to prove obviousness before the NZ Patent Office than before a court.

Fair basis and failure to disclose a best method are not specified grounds of opposition although they are available under revocation before a court.

Opposition does not preclude opponent from seeking revocation

If the opponent fails at opposition, a revocation action can still be brought in a court.

Further articles in this series

This is the second instalment of a multi-part series on New Zealand patent oppositions. Stay tuned for further articles: