The European Union Joint Research Centre has just released their report: "Scenarios for co-existence of genetically modified, conventional and organic crops in European agriculture"
The 145 page report is available on the Internet in PDF format here: http://www.jrc.cec.eu.int/GECrops/

The main conclusion that can be drawn is that GM contamination of conventional and organic crops is inevitable as a result of the introduction of GM varieties. The result will be higher production costs (up to 41% higher in the case of organic oil seed rape) for farmers in the EU. Some key quotes from the report are reproduced below.

Hope this is of interest.

Thanks & regards
Marcus Williamson
Editor, Genetically Modified Food - UK and World News
http://www.gmfoodnews.com/ 
 
On Oilseed Rape:

p. 51: "Summarising the results, it seems to be difficult for the farm types considered in the study, to achieve contamination levels below 0.3% employing current practices. A considerable reduction of in-field contamination could be achieved to the extent that even levels below 0.1% could be reached. Problems regarding the handling of the crop and the logistics of the farm (Farm 3) could be more difficult to solve. For this farm type, very low contamination levels of 0.1% could be impossible to accomplish."

On Maize:

p. 65: "Under the conditions selected for studying grain maize production, a very low threshold of 0.1% cannot be achieved, neither with current nor with changed practices, neither for organic nor for conventional farms, even if the GMO share in the region is only 10%. Potential seed impurities as well as post-harvest admixtures because of farm logistics render a very strict segregation impossible."

On Potato:

p.73: "Compared to oilseed rape or maize, potato seems to be a rather simple crop concerning probability of contamination, based on the different biological characteristics of the crop. The main problems are connected to volunteers and post-harvest handling of the crop. Contamination levels are in general estimated to be low (< 1%), even though a threshold of 0.1% would be very difficult to achieve. The assumption of baseline contamination levels of 0.01% for nearly each production step makes this impossible. The recommended change of farming practices could be used to further reduce contamination levels to increase a security margin, but are assumed to be not effective enough to enable a production below a 0.1% contamination level."

On Financial losses to organic farmers

p.104-105: "The long-term impacts of GM contamination on organic farms cannot be assessed totally at the moment since they are highly dependant on the exact shaping of a farming system which intends to minimise the unintended contamination with GM material. In cases where unintended contamination with GM material occurs every year (e. g. due to wide ranging cultivation of GM crops in a certain area), organic farms will lose their organic status and face severe problems to grow their crops according to the regulations given by the EU and the national authorities. In such a scenario it might be conceivable that it is almost impossible to grow organic crops so that the affected farms will face significant financial losses and economic problems.  However, in such cases the question of compensation payments will most probably be on the political agenda because organic farms in regions with high cultivation rates with GM crops will suffer damage of their incomes without being able to prevent contamination with GM material."

On Insurance

p.107: "All in all, there might be insufficient insurance coverage on farms in case of growing of GM crops. There are specific hurdles for insurance companies to offer (general of specific) policies, which cover the damage caused by adventitious contamination with GM material. Little if any experience is available to insurers in the EU on commercial risks associated with the deliberate release of GMOs or products containing GMOs. This applies for means for calculating likely loss patterns in this area as well. This absence of data promotes a fundamental doubt among insurance companies over the insurability of such commercial risks. The commercial risk profile of the use of genetic engineering in agriculture and the deliberate release of GMOs or products containing GMOs is extremely diversified and very difficult to quantify. In the view of the insurance industry, there is no clear perception of commercial risks involved in this area making this fields hard to measure and thus to insure."