Radiographers, who carry out scans on patients, have agreed to strike over pay in some parts of England.
Staff at 43 NHS trusts have enough votes to stage walkouts, ballot results reveal.
The Society of Radiographers says it is likely industrial action will go ahead in July, unless the government can improve their offer of a 5% pay rise this year and a cash payment for 2022.
Some junior doctors and consultants also plan to strike in July in England.
Radiographers carry out x-rays, MRI and CT scans, ultrasounds and breast screening, as well as radiotherapy for cancer patients.
More than 20,000 members of the Society of Radiographers were balloted.
Members in trusts including the Royal Marsden, University College London Hospitals, Liverpool University Hospitals and Sheffield Teaching Hospitals have a mandate to take strike action.
Dean Rogers, from the Society of Radiographers, said: “The radiography professionals on the front line know that low wages undermine efforts to create a stable NHS workforce, with sufficient staffing levels to ensure that all patients receive the best treatment possible.
“If the government wants to reduce NHS waiting lists and ensure that patients receive the treatment they need, when they need it, then it must urgently prioritise the recruitment and retention of radiography professionals.”
Tel: +44 (0) 141 946 6482
Address: Healthcare Skills Training International Ltd
West of Scotland Science Park
Block 7, Kelvin Campus
Glasgow G20 0SP