But the lucky ones are waiting for several thousands of pounds due in back-dated pay, although they were said today to be “very much in the minority”.

Agenda for Change is more than a pay deal that affects everyone working in the NHS across Scotland — with the exception of doctors and consultants, who negotiated separate arrangements.

The process has involved evaluating every job in a bid to ensure people are getting paid for the work they actually do, and not on the basis of an out-of-date job description that might date back decades. It is also intended to remove the anomaly of people doing similar jobs being paid different amounts.

But the process has proved to be much more complex and protracted than was expected, and people promised money are now frustrated and tired of waiting. When each individual’s job and pay have been reassessed, the settlement will be backdated to October, 2004.

Many staff had been hoping for a bumper pay packet in December, the target date when the Scottish Executive expect the back pay to be passed on to staff.

However, NHS Tayside chairman Peter Bates is now expressing concern that timescale is “just not doable”.

Worse, from the point of view of the thousands of staff expecting a pay boost, it seems the lengthy process of reviewing job descriptions and pay scales could all lead to nothing in terms of cash in hand.

NHS Tayside’s finance director David Clark said, “Plenty of people will be disappointed and not due anything.”

Robin Hunter of the public service union Unison said, “There will be small numbers who get large amounts. The majority of people will get something, but not a lot. Some could get several thousand pounds, but that would be very much the minority. The majority will probably get a few hundred.”

He said the cash was for around 18 months’ back pay, so for many people that would not add significant amounts to their salary initially, but he pointed out that people were being placed in a new pay structure that would allow them to move up the scale and earn more in future years.

While stressing he made no criticism of the staff working under pressure to meet the deadlines and process the huge numbers of job descriptions and payroll information, Mr Bates is obviously clearly concerned about his organisation’s ability to meet the deadline.

“If we don’t meet the targets it means staff won’t be paid and won’t get their back money,” he said.

“Staff have a right to expect this is fixed. I think this is going to be unbelievably difficult, and I have to say, managerially, I am not sure it can be done.”