The Government is facing the threat of strikes by nurses in protest at years of below inflation pay rises.
Members of the Royal College of Nursing voted overwhelmingly to support a ballot for industrial action. Another ballot would have to be held before any action is taken.
In the consultative ballot, nine out of 10 voiced support for action short of a strike while almost four out of five backed strikes.
More than 50,000 of the RCN’S members took part in the ballot.
The RCN’S annual conference in Liverpool today will discuss the next move..
The RCN has warned that low levels of pay are partly responsible for tens of thousands of unfilled nursing posts.
Nurses have suffered a 14% pay cut in real terms since 2010 because of a government cap on public sector pay, said the RCN.
A formal pay cap of 1% was introduced in 2015.
RCN general secretary Janet Davies has warned that years of pay cuts have left nurses struggling to make ends meet.
Jon Skewes, director of policy at the Royal College of Midwives, commented: "NHS staff have now seen seven years of pay restraint and with at least another three years on the horizon.
"Continuing pay restraint is a disastrous, unsustainable policy for maternity services and the NHS. We are working with other NHS trade unions to break the Government's policy of pay restraint.
"Back in 2014 we took the historic decision to take industrial action for the first time in our 134-year history.
"The RCM took a leading role in that dispute and the historic scenes of midwives and maternity support workers on the picket lines was a pivotal step in winning the dispute.
"The NHS is reliant on midwives', maternity support workers' and all other NHS staffs' goodwill and we want the Government to recognise that.
"We want to use the opportunity of the General Election to influence the Government to address the staffing crisis in the NHS and work to retain existing NHS staff in the service.
"We want the Government to show all NHS staff they are valued by allowing the NHS Pay Review Body to make an unfettered recommendation on NHS pay. Investment in NHS staff is an investment in high quality, safe care."
Dr Mark Porter, British Medical Association council chairman, said: "Year after year of real-terms pay cuts have had a damaging impact on the morale of frontline NHS staff.
"Ongoing pay restraint has seen doctors' pay fall by up to 17% in recent years, leading to staff shortages and impacting on patient care, and doctors across the country will agree with the very strong message sent today by nurses, that the pay cap is unfair, unacceptable and must be lifted.
"With the NHS at breaking point, politicians cannot continue to duck this issue.
"Investing in the NHS workforce and providing fair terms and conditions must be a priority for the next government, otherwise the NHS simply won't be able to attract and keep the frontline staff needed to deliver safe, high-quality patient care."