PM backs zoo's bid to bring pandas to the Capital

Zoo bosses said Mr Cameron had raised the issue during his official visit to Beijing earlier this month.

It comes as documents obtained by the Evening News show that First Minister Alex Salmond wrote to China's foreign minister in September, saying that he was hopeful that "oustanding issues" preventing the panda deal could be resolved.

David Windmill, outgoing chief executive of the Royal Zoological Society of Scotland, which owns the zoo, said the recent death of a giant panda in captivity in Japan had led the Chinese to re-negotiate clauses in the contract agreed with Edinburgh.

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Xing Xing, also known as Kou Kou, was on loan from China to Oji Zoo in Kobe, western Japan, when he reportedly died on the operating table during a procedure to extract semen for an attempt at artificial insemination.

Mr Windmill said: "Discussions and negotiations are still continuing. We are aware there were discussions during Prime Minister Cameron's recent visit to China.

"There are one or two problems - a giant panda died in Japan only a few months ago and as a result we had to re-negotiate clauses in the agreement."

Mr Windmill, who will step down as soon as his successor is found, denied that financial difficulties at the zoo were the real reason the panda agreement had not been reached.

It is understood the zoo is preparing to lay off 50 of its 200-strong full-time staff amid falling visitor numbers.

Mr Windmill added: "The giant pandas are about the longer-term development of the society. The recent news is about the short term. We're still hoping that the pandas will arrive in the back end of next year. It will take about a year to prepare things, so the sooner we reach agreement, the better."

It is now more than two years since a letter of intent was first signed between the UK and China outlining plans to bring the pandas to Edinburgh.

China charges foreign nations 500,000 a year to lease its pandas, but needs to be satisfied that adequate facilities are in place to care for the animals before giving approval.

In a heavily-censored letter from the First Minister to Chinese Foreign Minister Yang Jiechi released under Freedom of Information laws, Alex Salmond writes: "I am pleased to say that implementation of some of the actions agreed during my visit are moving forward quickly and am grateful for your encouragement and support.

"For example, the Royal Zoological Society of Scotland have held a further meeting with the CWCA (China Wildlife Conservation Association) to resolve the outstanding issues that will lead to the loan of two pandas to Edinburgh Zoo."