Staff working in more than 100 health trusts in England are being refused extra pay if they work on the day of the royal wedding, union chiefs have revealed.
Unite has conducted a study that found 115 NHS trusts have informed their nursing and medical staff they will only be paid normal rates if they are scheduled to work 29 April.
Bank holiday rates are being paid in NHS trusts in Wales, Scotland and Northern Ireland, Unite has claimed, with amounts ranging from an extra 60% to double pay.
But the union said a "significant" number of trusts in England were not acknowledging the day, a move that does not fall in line with the decision by the government to recognise the royal wedding as a bank holiday.
Unite national officer Rachael Maskell said: "These trusts still have time to do the right thing and recognise the valuable contribution NHS staff make to this country."
Unite said that under the national agreement for the NHS, called Agenda for Change, staff working during a bank holiday are entitled to an enhancement in their pay ranging from double to time plus 60%.
Dr Peter Carter, Chief Executive of the Royal College of Nursing (RCN), said the findings showed yet another example of a lack of consistency across the NHS.
"It's just another ingredient in making people think that they're not valued.
"It's really odd that staff in one of the four countries of the UK are not getting the same benefit as those in the other countries."