Nurses have been warned that if they do not pay the increased €150 registration fee due by January 1, they could face being struck off the Nursing and Midwifery Board of Ireland's register.
The warning comes as the nurse's union told its members they should only pay €100, the old rate for membership.
The HSE requires nurses and midwives to provide proof of registration with the NMBI by April 30, 2015. This year's registration fee sees a 50pc increase in the amount that nurses must pay.
General secretary for the Irish Nursing and Midwifery Organisation (INMO) Liam Doran believes nurses should only pay a €100 fee.
"I'm not quite sure why the board are insisting we pay by January 1 other than to intimidate nurses, it normally doesn't require receipt of payment until April or May," he said.
"We have no problem paying the €100 fee, but we don't agree with the idea of paying the 50pc increase," Mr Doran explained.
In the last three years the registration fee has almost doubled from the €80 it cost to register in 2012, while nurses salary's have decreased by between 14pc and 20pc.
A spokesman for the NMBI stated that the perception created that the board was being "intimidating" towards nurses was "utterly false" and said that although the increase in fees was "unfortunate, they are necessary for what is a self-funded regulatory board".
"The organisation has expanded and because we've no other source of income we depend on the registration fees" he added.
President of the INMO and a working nurse at Waterford Regional Hospital Claire Mahon admitted she felt let down by the NMBI for what she felt was a lack of transparency.
"I feel strongly about the increase in fees, for one because our salaries keep decreasing while the registration cost continues to increase. I also have no confidence in the board. They're expecting us to pay what is a large figure in comparison to last year, while they give us no direction or communication," Ms Mahon explained.
"When myself and my colleagues need advise because we don't feel safe in our working environment, we aren't helped."