The largest healthcare union has warned of a “winter of unrest for the NHS” as it revealed plans to ballot members for industrial action.

A meeting of the union’s healthcare executive agreed on Wednesday to seek an emergency vote at its annual healthcare conference on 15 April to obtain permission to ballot its 450,000 NHS members over potential industrial action. The move is a response to the government’s imposed pay deal.

In a letter to health secretary Jeremy Hunt, seen by HSJ, Unison’s head of health Christina McAnea said NHS staff “feel they have been treated unfairly and with contempt.”

She added: “A motion will be put to the floor, calling on the union to initiate a national challenge to your pay policy. Our members care deeply about their patients and the services in which they work and do not consider or take formal industrial action lightly.

“In my view, the decision from our health executive yesterday represents a significant step towards a summer and indeed winter of unrest for the NHS.”

She urged the health secretary to “pull back from the brink” and reconsider his position.

The action follows the health secretary’s decision to reject a 1 per cent pay deal for all staff last month.

Under the imposed deal staff eligible for an incremental rise will receive no separate cost of living pay rise while those staff at the top of their pay band will receive temporary, non-consolidated 1 per cent pay rises in this year and the next.

Jeremy Hunt has offered to give staff a permanent 1 per cent pay rise over the next two years if the unions agree to a freeze on incremental pay in 2015-16.

HSJ understands Unison will reject the offer of a deal as part of plans to prepare for possible industrial action.

The government claims the imposed deal will save £200m this year and is vital to protect frontline jobs.

A spokesperson for the DH said: “In the wake of the Francis Inquiry, our first priority must be to protect and properly staff the frontline. Giving staff a pay rise on top of increments would cost the equivalent of paying for 10,000 full time front line staff and could risk unsafe care.

“Our door is open to trade unions if they wish to discuss how we can make the NHS pay system fairer. If trade unions agree to freeze incremental pay next year, we would be able to give all NHS employed staff a consolidated one per cent pay rise for the next two years.”