The workers are demanding that Streeting takes a more active role in ensuring Barking, Havering and Redbridge University Hospitals NHS Trust puts forward an acceptable offer to bring their dispute to end.

Pathology staff are striking over plans to impose a new shift system and over the 'failure of the trust to tackle bullying, harassment, and discrimination within the department'.

In clinical engineering, staff strongly oppose the outsourcing of their department and the proposed transfer of roles to Siemens Healthineers. This would erode terms and conditions and would not benefit staff or patients, according to Unite the union.

The workers initially took three days of strike action over a range of issues in February. Fresh strikes began on Monday (9 March) and will end on Friday (13 March).

Unite general secretary Sharon Graham said: ‘These workers are dedicated to serving the NHS but have been left with no alternative but to continue striking.

‘As both health secretary and the local MP, Wes Streeting must intervene to ensure the trust ends a damaging dispute it is solely responsible for causing by putting forward an acceptable offer.'

In response, trust chief executive, Matthew Trainer, said: ‘We need to make changes to the shifts our staff work in pathology because we are one of the few trusts that don't have a 24/7 service. We recognise the impact this will have on colleagues who will be affected by this change and we're willing to offer a level of pay protection that is higher than elsewhere in the NHS.

‘We're keen to continue negotiating.'