Workers from across the NHS will walk out tonight in the service's first national strike for 18 years.
NHS Logistics will stage at least two 24-hour strikes, one to coincide with the Labour party conference. The first will start at 10pm tonight and the second will take place on Tuesday September 26th - the day Labour will be discussing health at the conference in Manchester.
The strike is over the "sell off" of NHS Logistics - which supplies hospitals with around 50,000 products including bedpans, syringes, bandages and food - to German delivery firm DHL.
Of the 900 staff who were balloted by Unison there was a 66 per cent turnout, and 74 per cent backed the move for industrial action.
Unison said there could be "absolutely no justification for privatising this service".
Head of health Karen Jennings said: "Taking strike action on the very day that health is to be debated by the Labour conference will put our members' protest centre stage.
"They have worked hard to build NHS Logistics into an award-winning service and don't deserve to be treated in this way. There is simply no logical explanation for this transfer."
Health secretary Patricia Hewitt recently insisted the NHS had to reform to survive, and yesterday said using the private sector to deliver NHS treatments would ensure extra funding was properly used.
The government also claimed the deal, which comes into force at the start of October, would help save £1 billion over ten years.
There have been concerns the strike could leave hospitals short on supplies, but the Department of Health denied that it would significantly disrupt NHS operations.
The union also agreed emergency plans to cover life-saving equipment during the strike.