The specialist health workers are demanding their roles are re-banded to reflect their knowledge, skills and training. At present, they are paid at band 2 of the NHS's Agenda for Change pay scale, but Unison argues that their knowledge, skills and training equal those of a band 3 worker.

The workers have now spent 118 days on strike, which is believed to be the longest continuous strike in NHS history.

McAnea said: ‘It's shocking Gloucestershire Hospitals NHS Foundation Trust are refusing to pay the phlebotomists fairly for the important jobs they do.'

In response, a spokesman for the trust, said: ‘The trust wants to resolve the Unison-led industrial action and will welcome the revised job description, plus any new evidence and information the phlebotomists wish to submit, in relation to the phlebotomy roles required in our hospitals.'