Two giant pandas are set to arrive at Edinburgh Zoo in Scotland on Sunday on a eagerly anticipated ten-year loan from China, agreed after years of high-level political and diplomatic negotiations.

Yang Guang (Sunshine) and Tian Tian (Sweetie) are a breeding pair and the zoo is hoping Tian Tian will give birth to cubs during her stay.

The pandas, which were both born in 2003 and have been living in Sichuan Province, will fly to Edinburgh on a Boeing 777 freighter courtesy of FedEx.

They will spend a couple of weeks settling in before being put on public display, and the zoo has already reported a huge spike in ticket sales.

Edinburgh Zoo is paying about $1 million (750,000 euros) a year to the Chinese authorities for the pandas, the first in Britain for 17 years.

It has built two seperate enclosures for the visitors, which are quite solitary, although they will be linked by a passageway dubbed the 'tunnel of love' in anticipation of their hoped-for mating.

Each area contains an indoor section and a large outdoor enclosure, comprising lots of plants, trees, a pond and somewhere for them to shelter from the sun, a spokeswoman for the zoo said.

The pandas are expected to eat 20 three-metre long bamboo stems a day between them, at a cost of up to 70,000 pounds a year, choosing from 25 different varieties, most of them imported from the Netherlands.

As of December 16, visitors to the zoo will be able to look in on the outdoor enclosure, while "panda-cams" placed at strategic locations will allow Internet users to watch the movements of Yang Guang during daylight hours.

"Everybody is very excited about their arrival," the zoo spokeswoman said.

The agreement to loan the pandas was announced in January following five years of negotiations, and experts from the China Wildlife Conservation Association gave the final go-ahead after a visit to Scotland in October.

Chinese ambassador Liu Xiaoming said the loan represented an important step in researching the animals, as well as an important gesture of friendship.

"Tian Tian and Yang Guangs arrival in the UK is part of a 10-year joint research programme to find out how human-bred pandas can survive in the wild," he said ahead of their arrival.

"But this is about much more than conservation. It is also about science, culture, education and above all friendship and partnership. Through these themes we expect pandas to bring China and Britain even closer together."

He added: "This is an excellent window into grasping Chinas commitment to peaceful development, desire for cooperation and quest for harmony with the world."

However, animal welfare groups have condemned the agreement.

"Wild animals suffer tremendously both physically and mentally from the frustration of life in captivity and often display neurotic behaviour such as incessant pacing, swaying, and bar-biting," said campaign group PETA.

"If the zoo were serious about helping pandas, they would be asking the public to donate to schemes that protect pandas in their native habitats."