Unison - the UK's largest public-sector union with 450,000 NHS employees - is threatening to seek a judicial review of the proposed NHS reforms, in the backdrop of health trusts confirming 11,000 job losses within the NHS.

The union has said the proposals outlined in the Andrew Lansley White Paper have not been given due consultation before being implemented, thus making them unlawful. In a letter to NHS chief executive Sir David Nicholson, Unison warned that it will seek "urgent judicial review" if a satisfactory response was not received within seven days to its concerns.

Karen Jennings, Unison's head of health, said hospital chiefs were being "pressurised into rash decisions" and the proposed cuts would forever change the NHS. "These sweeping changes were not part of any party manifesto and it is outrageous that these changes are being brought in without consulting the public, patients, staff and unions," she added.

The white paper published last month lays down reform proposals such as changes to ambulance response targets and a privatisation plan for an NHS employee agency which provides nurses and other health workers to hospitals.