The senior council of the Royal College of Nursing was due to meet yesterday to discuss the government's pay offer of 2.5 per cent, staged over the course of the year.
Members were expected to use the private meeting to discuss whether to ballot members.
Ministers rejected the independent pay review body's recommendation of a 2.5 per cent rise to be paid in full from April.
This means many NHS workers will receive a pay rise of 1.9 per cent averaged out over the year.
Other unions discussing whether to move ahead with industrial action include Unison, Unite, the Society of Radiographers and GMB.