It was widely reported that the protocol would allow countries to ban the import of a genetically modified crops and foods and to enforce labeling of such foods. The official line is that the protocol puts trade and the environment on equal footing and many environmental groups have thus given favourable a reaction

In reality however, a clause added at the end of the negotiations ensures that the new protocol does not override other international agreements, including World Trade Organisation free trade rules. Under WTO rules imports of GMO's cannot be banned. The WTO has ruled that the European Union's ban on the import of GE hormone treated beef is illegal. The addition of the clause was a victory for the governments of the US and the other major agricultural exporters, Argentina, Australia, Canada, Chile and Uruguay, known as the Miami Group, who want to be free to export GE foods.

The Miami Group also persuaded the signatories to put off for at least two years from the pact's implementation proposals to track and regulate global shipments of GE foodstuffs

SOURCES
"Critics Fear New Treaty Subordinates Biosafety to Trade" Danielle Knight, Inter Press Service, Feb 1st, 2000
http://www.igc.org/trac/headlines/2000/29.html

UKabc, Cartagena Protocol page
http://ds.dial.pipex.com/ukfg/UKabc/cartagena.htm '