Colin Lynch, who now lives in western Australia, said he is devastated that his mother - who was diagnosed with lung cancer while on holiday in Perth three months ago - has been forced to wait almost two weeks to be admitted to the province's only specialist inpatient cancer treatment centre at Belfast City Hospital because of a lack of beds.

And today he issued an urgent plea to health chiefs, who have categorised his mother's case as an emergency, to offer her immediate treatment here or transfer her to another UK hospital that has the facilities to treat her.

Margaret Lynch was offered immediate treatment by doctors in Perth in October when she was first diagnosed.

However, the 70-year-old Portrush woman wanted to recuperate in familiar surroundings and opted to return home to Northern Ireland expecting to receive medical attention straight away.

Almost two weeks ago - while still awaiting treatment - Margaret collapsed breaking her collar bone and was rushed to Causeway Hospital where she was subsequently diagnosed with secondary cancer in the brain.

Due to the discovery of a second tumour Margaret has now been listed as an emergency case requiring inpatient treatment, but she cannot be transferred from the Causeway Hospital to the Cancer Centre at Belfast City Hospital - the only hospital in the province that can offer inpatient radiotherapy and chemotherapy - because there are not enough beds.

Her son Colin said he believes that failings within the National Health Service and a lack of facilities have let his mother down.

"When I asked if it was possible to find a bed in another hospital somewhere in the UK where my mother could get treatment I was told it was not an option and that it would be better to wait around for a bed to become free," Colin told the Belfast Telegraph.

He added: "Responsibility to provide care is with the provider. Duty of care cannot be constrained by lack of resource. It is very frustrating that a 70-year- old woman, a wonderful mother, a great friend and someone I'm proud of in every way possible, has been abandoned to a system that doesn't allow for initiative or duty of care to be extended beyond the walls of the building where she has been lying for several days."

A spokeswoman for Belfast City Hospital said that Margaret was referred to Belfast City Hospital on January 16 and is currently on the "emergency" list for admission to the 84-bed Cancer Centre.

She added: "Generally, depending on the urgency, there is a two to four week wait for admission; however, in the event of a patient needing immediate treatment they will be admitted the same day.

"Patients come to the Cancer Centre in Belfast if they require inpatient chemotherapy or radiotherapy.

"Otherwise patients are cared for and treated at the local cancer units. "

The Causeway Hospital said it could not comment on the treatment of individual patients.