Hundreds of healthcare workers in Blackpool who are members of a union are set to walk out in a row over wages.
Unison said a 48-hour strike of its members was set to begin at Blackpool Victoria, Clifton and Fleetwood hospitals on Monday from 07:00 BST.
Staff say Blackpool Teaching Hospitals NHS Foundation Trust, which runs the hospitals, is refusing to compensate them fairly for work carried out, such as taking blood, performing electrocardiogram (ECG) tests and inserting cannulas, when they were on the wrong grade.
The trust has been approached by the BBC to comment, but Unison said the trust had accepted healthcare assistants had been performing extra duties and would provide back pay.
However, the union accuses senior managers are trying to “claw back” some of the money owed to staff, even though NHS policy says nobody should be worse off as a result of a promotion.
It said the trust’s refusal to settle up is out of step with what is happening elsewhere in the region and around the country.
Fifteen health trusts in north-west England had moved their healthcare assistants to the higher rate and given them back pay, according to the Local Democracy Reporting Service.
Since 2021, more than 60 NHS trusts in England and Wales have agreed deals on regrading and back pay for more than 40,000 healthcare workers.
Unison North West regional manager, Dan Smith, said: “It’s outrageous the trust is refusing to pay staff properly for all the extra work they’ve done.
“Healthcare assistants have been working above their pay grade for years, in some cases decades, and it’s only right they’re fairly compensated.
“Hospital managers need to recognise the strength of feeling on this issue. They should follow the example of other trusts in the region and stop trying to claw back money their employees are entitled to.”