Health workers have threatened industrial action after blasting the government's "poxy" offer of a three-year pay deal worth 8.1% to more than a million NHS staff.
At its national health workers conference in Manchester, Unison agreed that the union's 500,000 NHS members should hold a ballot next month on the proposed deal.
Some delegates wanted the union to move straight to an industrial action ballot as the only way of improving the offer of 2.75% this year and future rises of around 2.5% a year.
But delegates voted instead to give the members a chance to accept or reject the planned agreement, although warning of industrial action if it is turned down.
The two-hour debate became heated at points, with some speakers attacking the government and Prime Minister Gordon Brown for wanting to give health workers three years of below inflation rises.
Sarah Creagh, a nurse from Bristol, said: "The government is spending billions of pounds in Iraq and on Northern Rock and on wasting money on PFI contracts, yet health workers have to suffer years of pay cuts."
Adrian O'Malley, from Wakefield, said the deal was "poxy", adding that health workers should join teachers, lecturers and civil servants in taking strike action over pay.