The NHS workers have been regraded to a higher band of the NHS Agenda for Change salary scale to reflect increasingly complex tasks, but Unison says they deserve adequate back pay to reflect the extra work they've been doing above their pay rate for many years.

The trust awarded seven months' money, but the union says this should be far higher.

In a ballot, 99.4% of staff said they will walk out unless the employer comes back with a better deal to compensate them for the extra work they have done.

Unison Northern regional secretary Clare Williams said: 'Despite repeated chances to do the right thing, the trust has failed to improve the offer on back pay. Being paid for just a matter of months rather than years fails to reflect the complexity of the tasks they've been doing for so long.

'The trust should recognise the vital role healthcare assistants play and ensure staff receive decent compensation for their work, instead of forcing them into a strike no one wants.'

In response, a County Durham and Darlington NHS Foundation Trust spokesperson, said: ‘We are continuing to engage in constructive discussions with Unison to reach a resolution on this matter.

'Our priority remains ensuring the safe delivery of high-quality care for our patients, and we are working closely with staff and union representatives to avoid any potential disruption.'

The strike dates have yet to be finalised.