The Unite union workers within the Rapid Response Team are taking action over working conditions at the London hospital.

Unite general secretary Sharon Graham said: ‘These are some of the most valuable workers in the NHS doing unseen work to keep patients and other staff safe. They work in dangerous, infectious areas of the hospital and provide a cleaning service to keep disease outbreaks under control. Yet they are being treated with disdain by the trust.'

The workers are taking action over a number of concerns, including: the quality of rest facilities; lack of engagement with Unite over the usage of harmful chemicals; and continued use of bank staff instead of hiring additional staff on permanent contracts.

A spokesperson for Guy's and St Thomas' NHS Foundation Trust said: ‘We want all our staff to feel supported at work which is why we have been working hard for many weeks to bring an end to this dispute with our rapid response cleaners. We have listened to their concerns and made several changes to address them.

‘It is regrettable that Unite are determined to press ahead with this industrial action despite the progress we have made together. We have robust contingency plans in place to mitigate the action and ensure services remain unaffected. We remain committed to working with our staff to resolve this dispute as soon as possible.'

The trust said all cleaning shifts will be covered during industrial action.

A spokesperson said the trust was also investing in upgrading the rest facilities at Guy's Hospital with a new kitchen and furniture.