Unite, the union representing the workers, says the trust has failed to address the fact that the workers are on the pay band below what they should be for the work they carry out.

The trust has also agreed to undertake extra work for another trust that the microbiology workers will have to carry out, increasing the number of call-outs during nights and weekends, the union says. As a result, out-of-hours rotas have been changed without consultation or regard to current workloads.

The workers previously took strike action from 18 to 25 December and fresh strikes will take place from 9-11 February and from 18-20 February. 

Unite general secretary, Sharon Graham, said: 'Airedale trust's leadership are treating these staff disgracefully. They are already being paid too little, and now the trust is demanding they take on out-of-hours work on top of heavy existing workloads. These workers are entirely right to strike and have Unite's full support.'

In response, Mark Harrison, director of operations for Integrated Pathology Solutions, said: ‘We have listened to the views of our colleagues and have continued productive negotiations with Unite. We are not asking colleagues to take on extra out-of-hours work.  We would also never change any rotas without consultation of colleagues or consideration of workloads.

‘Our commitment to resolve this dispute remains, and we will continue to work in partnership with Unite to do so.  In the meantime we are working hard to minimise disruption during this period of industrial action.'