Hospital staff have voted overwhelmingly in favour of strike action, in response to plans to remove them from the NHS payroll.
Workers at the Mid Yorkshire NHS Hospitals Trust, which runs Pinderfields, Pontefract and Dewsbury hospitals, are set to take industrial action next month.
The Trust wants to transfer the contracts of hospital cleaners, canteen staff, IT staff and maintenance workers to a separate company. It means that they would lose NHS terms and conditions, and their contracts could be sold to a private firm.
Unions say this would create a "two-tier workforce" and have branded the plans an "insult" to staff.
The Trust said they wanted to work with unions and had not yet received permission from the Government to go ahead with the plans.
More than 97 per cent of those balloted voted in favour of striking. There was a turnout of 58 per cent.
Adrian O'Malley, regional branch secretary of UNISON, said the result had sent a "clear message" to the Trust's management.
He said: "At the moment, strike action is definitely going to happen.
"Members are really angry and to say to these people that they won't be part of the NHS is an insult. They don't work in hotels.
"The work that they do has a direct impact on patient care. If the hospital is not clean it suffers. If there's no food, then it suffers.
"At the end of the day, we want discussions with management and we want a commitment from them that there won't be a two-tier workforce."
An exact date for strike action has not yet been decided, though Mr O'Malley said it was likely to take place in July.
Staff will withdraw their labour for either "one or two days," he added.
Jules Preston, chairman of the Trust said: “I can confirm that we have received the results of the ballot from Unison and that its members have voted in favour of pursuing strike action.
"As yet we have not received the required 14 days’ notice as to when the strike action could take place.
“I wish to make it clear that the Board has agreed to progress to a final business case but needs approval by the Secretary of State for Health and Social Care before a final decision on the Wholly Owned Subsidiary (WOS) can be made.
“In the meantime we have invited the unions to work with us – with the first meeting having taken place on June 12 - to explore the various options available to us from a staffing model point of view.
"A briefing has taken place for all those colleagues who could be involved in the WOS, should we be given the permission to proceed, and executive directors will be holding additional briefing sessions in the coming months.”