Two African countries are trying to open a new breach in the worldwide ivory trade ban, which conservationists fear could lead to more African elephants being slaughtered by poachers.
Environmental campaigners have called on Britain to take a clear lead in opposing the proposals by Tanzania and Zambia to sell their ivory stocks, which will be voted on at the next meeting of the Convention on International Trade in Endangered Species (CITES) in Qatar in March.
Other African countries, led by Kenya and Mali, are strongly opposed to the idea, and are sending representatives to Brussels this week to urge the EU not to support it.
If it went ahead, the sale would be the third "one-off" auction of ivory since the world ban came into force, 20 years ago last week.
The ban was initially successful in halting the huge scale of elephant killing of the 1980s, when Africa's elephant population crashed from 1,300,000 to 625,000 in a decade.
But following the most recent sale, in November 2008, of 100 tonnes of ivory owned by Botswana, Namibia, Zimbabwe and South Africa -- bought by dealers from China and Japan -- there has been an upsurge in worldwide seizures of illegal ivory, and of elephant poaching.
It is thought that the resumption of any trading creates a market into which illegal poached ivory can be laundered, thus boosting demand.
Reports suggest that at least 15 tonnes of African ivory -- the equivalent of up to 1,500 elephants -- were seized in, or en route to, Asia in the past year.
Allan Thornton, head of the Environmental Investigation Agency in Britain, which provided much of the evidence of poaching which led to the original ban, said: "If this new sale went ahead it would be throwing fuel on the fire."
Conservationists say CITES' recommendations regarding the last two sales, in 1997 as well as 2008, were that they should go ahead, and the European Union voting block within the convention, did not oppose them.