A PAY rise promised to more than 155,000 NHS staff in Scotland has been hit by further delays, sparking anger and disappointment.

Workers ranging from porters and nurses to doctors will now have to wait until next month for the extra money, which was due to be paid from April 1.

Although the rise will be backdated, staff may have to wait even longer for this catch-up money.

Willie Duffy, head of health for trade union Unison in Scotland, said: "Clearly this is unacceptable. We signed off a circular [instructing health boards to implement the pay rise] three weeks ago. I was assured it would be in the May pay packet.

"Our members will be angry about this given that they have had the pay rise in England, Northern Ireland and Wales and we are still waiting."

When The Herald revealed in April the 1% pay rise would be late in Scotland the Scottish Government said there had been extra work north of the Border because an extra supplement was being given to the lowest paid.

However, Mr Duffy said he had no idea why there had been another delay. He continued: "I am going to be writing to the cabinet secretary for health [Alex Neil] to express my anger at the way the whole process has been handled and the fact we were assured it would be paid in May. I will be asking for an explanation from him as to why it has not been."

The Royal College of Nursing Scotland has also expressed disappointment. Associate director Norman Provan said: "We already know the Scottish Government failed to instruct boards to implement this year's pay increase on time, which was unfortunate, and means that our members will experience a delay in receiving their pay rise.

"We're now aware of a possible further delay in paying staff. This is disappointing. Although their increase will be backdated, a further delay would be yet another burden on nurses when they're already facing unprecedented financial pressure, following a two-year pay freeze and increased pension contributions. The Government must avoid any delay in paying staff what they're due in future."

Jackie Baillie, health spokeswoman for Scottish Labour, lodged a parliamentary question asking Mr Neil about the delayed pay rise.

She said: "It is shocking the SNP Government can't get our NHS staff pay right. Our NHS staff work their socks off and it isn't good enough, especially as the cost of living is rising, for small pay awards not to be paid on time.

"After this failure came to light earlier this year, I would have hoped that Alex Neil would have got to grips with it and sorted the problem out. He hasn't."

A spokesperson for the Scottish Government said: "All NHS staff covered by agenda for change will see a 1% increase in salary from April 1, 2013.

"There has been extra work required to create the circular, as in Scotland we are protecting family incomes for the lowest-paid by providing an increase of £250 a year for those paid less than £21,000. The circular has now been issued allowing boards to pay the increased salary rates to staff. We understand that the increase in pay will be included in June salaries, and that staff will receive arrears as soon as practicably possible."

The delay emerged on a day new figures revealed that one in 10 patients in A&E units were not treated within the target time in January.

Meanwhile, Alex Neil announced thousands more operations would be carried out to cope with a "significant increase" in people needing cataract and joint surgery.