The three largest nursing unions are divided over whether to take further action over proposed changes to public sector pensions.
Unite/CPHVA has rejected the government's revised deal and says up to 100,000 of its NHS members will take part in a 'day of action', including strikes, on 10 May. Neither Unison nor the RCN has called for members to take similar steps.
Unison says it has no mandate to strike after around half of members participating in a ballot voted to accept government proposals. Less than 15 per cent of eligible members voted, with 50.4 per cent opting to reject the government's plans.
A similar ballot by the RCN took place in February, with 62 per cent of respondents voting to reject the government's proposals. Turnout was again poor, at just over 16 per cent.
Last week, the Royal College of Midwives said it had 'reluctantly' accepted the pension plans following a consultation with members.
Negotiations between ministers and union representatives resulted in a revised pension offer in December, which would see nurses earning between £15,000 and £26,557 - and those less than 10 years from retirement - exempted from any rise in pension contributions next year.
Unite's lead nursing officer Barrie Brown conceded that the day of action would benefit from RCN and Unison support, but said it would go ahead regardless.
'More than 94 per cent of our members voted to reject the government's offer, so we feel we have a very strong mandate,' he said. Turnout in the ballot was 25 per cent.
NHS Employers warned that trusts had been given insufficient time to plan for the strike, claiming this would exacerbate disruption and lead to delays in hospital tests and discharges. Director Dean Royles said: 'I recognise the union is disenamoured about pensions but patients must be our first priority.'
Mr Brown claimed Mr Royles had 'painted a very misleading picture'.
'We have held discussions with NHS Employers, and gave notice of our plans several days in advance of the date by which we were required to by law,' he said.
The strike is supported by the Public and Commercial Services union and the University and College Union.