Almost half a million health workers are to vote on the Government's controversial public sector pension reforms, with rejection leading to the prospect of fresh industrial action.
Unison said its 450,000 NHS members, including nurses, therapists, paramedics, cooks, cleaners and porters, will vote in the coming weeks on whether to accept proposals for a new pension scheme.
Christina McAnea, Unison's head of health, said: "The union will be giving full and open information on what it will mean for individual members' pensions, so they are in the best position to make an informed decision.
"We are still disappointed that the proposals don't meet all our aspirations for health workers, particularly around the retirement age, but the ballot papers will also recognise that rejecting the offer would require members to take further industrial action.
"We have given a commitment from day one that it is for our members to decide and we are keeping to that commitment. This is a massive consultation exercise, far bigger than any other in the trade union movement."
Unison said the proposals maintained a defined benefit scheme with a move towards career average in 2015, while health workers earning less than £26,000 a year will not see an increase in their pension payments this year.
Unison took part in last year's huge strike by more than one-and-a-half million workers.
The National Union of Teachers (NUT) today said it will be debating a priority motion on pensions at its Easter conference next month.
The union also took part in last year's walkout, and its London members are due to stage a one-day strike next Wednesday as part of the NUT's continued campaign against the Government's pension plans.
NUT general secretary Christine Blower said the wording of the motion had not yet been decided.
She said: "Clearly what it will be about is how we maintain momentum of a campaign which is, necessarily, a longish campaign, and what the milestones in that campaign are."