A Universal Credit glitch means frontline healthcare workers could have their Covid bonus wiped out.
Thousands of NHS staff were promised the bonus last month for their effort throughout the pandemic.
However, NHS workers will lose their bonus or a part of their bonus if they or their partners claim Universal Credit.
Officials have said the £735 one-off payment - which averages at around £500 after deductions - could be significantly reduced or even wiped out.
This is in large part due to the way in which benefit calculations are made.
The amount of Universal Credit you get is determined by how much you earn. Therefore, the more you earn, the less you get in the following month.
A spokesman from the Department for Work and Pensions said: “We thank all NHS staff who have worked tirelessly throughout the pandemic.
“ Universal Credit is a means tested benefit – bonuses are treated as earnings and payments are gradually reduced as someone’s earnings increase.”
News of possible deductions to the one-off payment, has been met with dismay and seething disappointment from NHS workers.
One nursing assistant told Wales Online : "I didn't see my kids for six weeks at the start of the pandemic - not only did I sacrifice my time with them but I was also risking my life.
“This bonus is getting taxed at source so it's more than £200 less than the payment that's been given.
"And now I could end up losing more of that because as a working single parent I claim some benefits. It feels like a massive slap in the face to be honest."
For every additional pound earned by someone on Universal Credit - whether through higher wages, additional hours or bonus payments - benefit entitlement reduces by 63p, not the full £1. This means that workers should retain at least part of their bonus.
