The top heart surgeon who will operate on Lily Cater yesterday spoke of his frustration at not being able to carry out her surgery.

Lily, of Low Moor, Bradford, has had her surgery cancelled nine times.

David Barron, who operates in the cardiac unit at Birmingham Children's Hospital, said although they had all the facilities to carry out the surgery, the hospital did not have enough specialist nurses to look after Lily.

"There is a national shortage of specialist intensive care nurses and Birmingham, like all other hospitals, is affected by this," he said.

"Of course it is frustrating for us when that shortage has such a terrible impact on people's lives, and the hospital and I are making every effort to ensure we can operate on Lily on Monday."

Two-year-old Lily was born with a rare heart condition called pulmonary atresia. If untreated she will die before the age of five. Her mother Michala Cater said she sympathised with the position.

"I know the hospital staff are doing all they can," she said. "It's not their fault but there are obviously major financial problems with the NHS and the result of that is that sick children like Lily are not getting the surgery they need." Lily needs to be in the intensive care unit for days after her operation.

"If there has been a long-term shortage of these nurses more should have been done by the Department of Health to address it," said Mrs Cater.

"All those resources going to waste and Lily's operation being cancelled time after time, it's shocking. I can't believe that the Government is doing nothing to make the situation better."

The intensive care unit could run 19 beds but he said: "It requires a staff of 140 nurses to manage it at capacity and we have only 120."

The hospital has one of the busiest heart units in the UK.

Each year it carries out 600 therapeutic and diagnostic catheterisations (examination of the heart using x-ray imaging and pressure measurement by insertion of a fine wire/camera) and a similar number of heart operations.

Lily is now waiting to see if she will be called to the hospital on Monday for an operation on Tuesday.

Hospital spokesman Alan Taman said: "There is currently a shortage of 20 full-time posts in the Paediatric Intensive Care Unit (PICU) at Birmingham Children's Hospital. The full complement is 140. This is being addressed with extra in-house training and recruitment, coupled with rigorous and continual review of clinical urgency, so that emergency care is protected."

He added that the specialist nature of the care meant it couldn't be covered by agency nurses.