Support staff in major Dublin hospitals have voted to go on strike.

Porters, catering staff and lab assistants are angry about pay cuts and changes to working conditions.

SIPTU says that the industrial action will affect St Vincent's University Hospital, Beaumont, the Mater, Tallaght and St Luke's hospitals and the National Maternity Hospital at Holles Street.

More than 1,500 members have voted for the action, which SIPTU says is to "to resist any further attempt by management to cut our member's pay by removing them from rosters during unsocial hours and weekends and replacing them with interns."

SIPTU organiser Paul Bell has told the Health Service Executive (HSE) and the management of the balloted hospitals that the Croke Park and Haddington Road agreements contain provisions which protect the earnings of low paid workers in the health service.

"It is remarkable that at a time when senior managers in some voluntary hospitals have had top up payments to their salaries ring-fenced and also when the HSE and the government have seen fit to award pay increases to the highest paid medical workers in the State's health service that it is the lowest paid who are expected to take further hits to their take home pay. That it is simply unacceptable," Mr Bell said.