Members of the Unite union, representing health visitors and NHS support staff, are to be balloted on strike action later in the summer.
This means a strike could take place in the autumn if the ballot supports it.
According to Unite, the indicative ballot of 90,000 staff had a response rate of 27%, with 95% calling for a ballot on industrial action short of a strike and 75% supporting a strike ballot.
Unite Assistant General Secretary Gail Cartmail said: ‘This call for a ballot on industrial action is unprecedented in the NHS. It sends a very clear message that our members are angry and frustrated at being asked to accept this woefully inadequate three year pay deal.’
The three-year deal was negotiated by Unison and the RCN. It will come into effect from next month because the two unions have a veto because of their larger size.