Set to take root in July at the EPO's Enlarged Board of Appeal (EBoA), the hearing will consolidate arguments pertaining to the high-profile 'broccoli' and 'tomatoes' cases, which have stirred strong views in the agricultural sector.

Concerning a brassica with enhanced anti-carcinogenic properties and a tomato with reduced water content, the hearing will tackle three major issues around human intervention and whether the species in question could occur in nature.

Both patents have lengthy and controversial histories. 'Broccoli' – aka European Patent 1069819 – was awarded to Plant Bioscience Ltd in 2002 and attracted its first opposition in April 2003 from Syngenta Participations AG. Meanwhile, 'Tomatoes' – European Patent 1211926 – was granted to Israel's Ministry of Agriculture in 2003, meeting a challenge from Unilever in August 2004. The terms of the oppositions are so similar that the forthcoming last-resort actions to settle them have been brought together in one set of proceedings.

One of the most significant flanks of opposition to the patents comes from the No Patents on Seeds coalition, comprised of several non-governmental organisations such as the Berne Declaration, Swissaid and Greenpeace. The coalition argues that, in the case of each patent, the human action required to create the end product amounts to 'conventional breeding' – a form of cultivation excluded from patentability under the European Patent Convention (EPC).

According to Article 53 of the EPC, 'essentially biological processes for the production of plants or animals' are classed as excluded subject matter – as distinct from genetic, or microbiological, breeding, which leads to species and varieties that are unlikely to occur in nature.

The tangle of issues around the patents covers legal, ideological, industrial and political ground. Syngenta, itself a major force in plant biotech, used part of a recent position paper to argue in favour of the farmer's right to save seeds from harvests to invest in future crops – a right, it says, that should continue to be excluded from the scope of IP protection.

This view chimes with that of the No Patents on Seeds coalition, which contends that 'the technical input required in [most seed patents] is relatively minor or even trivial and can hardly be seen as inventive'. Nevertheless, the coalition says, more than 70 patents on conventional breeding have already been granted in Europe. In the coalition's opinion, this brings the threat of 'increase of seed prices and decrease of seed choices for farmers'.

Poised to set a precedent for whether the products of conventional breeding can continue to be excluded from patentability, the EBoA hearing will examine three questions:

1. Does a non-microbiological process for the production of plants consisting of steps of crossing and selecting plants fall under the exclusion of Article 53 only if this process matches steps that could already occur in nature?
2. If (1) is answered in the negative, does a non-microbiological process for the production of plants comprising those steps escape the exclusion of Article 53 merely because it contains, as part of its steps, an additional technical feature?
3. If (2) is answered in the negative, what are the criteria for distinguishing between non-microbiological plant production processes excluded from patent protection under Article 53 and non-excluded ones? Is it relevant where the essence of the claimed invention lies and/or whether the technical feature contributes something to the claimed invention beyond a trivial level?

The hearing begins on 20 July and should provide plenty of food for thought.