Foundations have already been laid for the £2.9m lecture theatre, which is part of a wider regeneration of BRI's buildings, including wards and patient areas, existing theatre, library, store rooms and kitchen.

The hospital has received a cash boost of £500,000 from a Yorkshire healthcare organisation to meet part of the costs.

The grant, from Sovereign Health Care, a not-for-profit organisation which provides health-care cash plans to private and corporate clients throughout the UK, will cover more than a sixth of the cost of the new theatre, which is expected to be completed by the end of the year.

David Wilkinson, deputy medical director of medical education for Bradford Teaching Hospitals NHS Foundation Trust, said: "We are really pleased to start building work. The lecture theatre reflects the general expansion of the foundation trust and represents a big boost to our education and teaching programme.

"There is no other venue of this size available to the foundation trust at the moment, which means talks and training sessions for large numbers of doctors, nurses, non-medical staff and medical students currently have to be split.

"We are very grateful to Sovereign Health Care for its substantial contribution to the cost of this aesthetically pleasing building, which I am sure will be a place people will remember and want to visit again and again."

Brenville Construction, the main contractor, has excavated 2,500 tonnes of earth from the sloping site, so that the two-storey building can sit three metres below ground level in order to blend in with its surroundings.

With seating for 200, it will be double the size of the existing auditorium. It has also been designed to provide optimum acoustics and includes latest IT facilities such as audience feedback.

The building will take the form of a large domed wooden pod encased in an external wall of glass. The plywood dome itself is being created off-site ready to be put together like a jigsaw.

David Lewis, chief executive of Bradford-based Sovereign Health Care, said: "It's going to be a fantastic state-of-the art resource that will be of great benefit to health professionals, students and ultimately patients.

"We are delighted to be able to contribute to this excellent expansion of facilities at Bradford Royal Infirmary."