Last minute negotiations are going on in China in the hope that Gordon Brown will be able to sign a deal to bring two Giant Pandas to Edinburgh Zoo.
However, Advocates for Animals have stepped up their campaign to block the deal saying the pandas are being used as "political and commercial pawns".
The zoo said it would be helping with a worldwide breeding programme to save the Giant Panda.
It was hoped the final details would be settled in time for Gordon Brown to sign off the agreement while he is at the Olympic closing ceremony in Beijing.
Ross Minett, Advocates for Animals campaigns' director, said: "To learn that a pair of Giant Pandas may be used in this unethical manner reflects poorly on Scotland's reputation and the Scottish and UK Governments.