The Duke and Duchess of Cambridge are to visit a Rolls-Royce aircraft engine factory in Singapore in support of the famous firm.

William and Kate, who are touring the region in celebration of the Queen's Diamond Jubilee, will unveil the first operational engine produced by the plant which opened earlier this year.

Before the Duke makes a speech to staff, the royal couple will be taken on a tour of the high-tech site where they will have a chance to meet employees, view the engines being assembled and watch the dramatic sight and sound of one being tested.

When fully up and running the factory is expected to produce 250 engines a year, including models for the Airbus A380, the double-deck, wide bodied jet.

During the day the royal couple will also visit an artificial rainforest mountain in the Cloud Forest Conservatory - one of two large glass domes that are part of Singapore's Gardens by the Bay attraction.

Their tour of the city-state also takes them to its first satellite housing estate, named Queenstown after the monarch, to see Singapore's public housing programme and view a cultural performance that showcases the three main cultures of Singapore - Chinese, Malay and Indian.

A short distance away is the Rainbow Centre, a school and community centre for children with special needs,where William will spend time with youngsters playing sports while Kate meets others engaged in arts therapy classes.

On Tuesday, the Duke fulfilled his mother's wish to see an orchid named in her honour and movingly described the bloom as beautiful. Diana, Princess of Wales was killed in a car crash in August 1997 just two weeks before she was due to visit the stunning flower in Singapore.

William, with Kate, has completed that trip and in a poignant moment suggested it "was a shame" his mother was not able to see the delicate flowers of the Dendrobium Memoria Princess Diana orchid for herself.

The visit to the bloom in Singapore Botanic Gardens was the first stop on a nine-day Diamond Jubilee tour that will also take the royal couple to Malaysia, the Solomon Islands and Tuvalu.