Protest by Great Western Hospital strikers
Cleaners and porters from the Great Western Hospital in Swindon have protested outside their management's headquarters in Wolverhampton.
It comes on the third day of strike action in a dispute between GMB union members and employer Carillion over bullying allegations.
Workers also protested at the site of the new Library of Birmingham, which is being built by Carillion.
The firm said it took allegations of bullying extremely seriously.
The union submitted a formal complaint by 109 members of staff over allegations of bullying and harassment in December.
GMB regional officer Carol Valley said the protests had gone well with lots of support from the public.
"While we were outside Carillion's HQ, a member of senior management came down and she listened to our concerns and said she would feed this back to the bosses.
"We're meeting with our members later this evening [Wednesday] to decide what our next course of action is.
"So far, Carillion haven't asked for any further talks but we are willing to talk to the management whenever," Ms Valley added.
A Carillion spokesman said the grievance was being fully investigated but added it was disappointed the action is taking place.
Porters, cleaners and domestic staff at the hospital also staged 24-hour walk-outs on 14 February, 21 February and 23 February.