The Government suffered a fresh blow to its hopes of ending the bitter row over pensions when nurses voted against the controversial reforms.
The Royal College of Nursing said its members rejected the proposed changes by 62%, although on a low turnout of just over 16%.
The nurses are the latest group of public sector employees to refuse to accept the Government's planned pension changes amid warnings of fresh strikes.
The RCN said the reforms were rejected by 41,009 to 24,533 in a ballot among nurses across the UK.
Professor Kath McCourt, chairman of the RCN Council, said: "While the members who voted expressed a clear view, showing their anger at the Government proposals, we are disappointed that more of our members did not take the opportunity to vote.
"We will now, as a matter of urgency, meeting with other unions who are at varying stages in their own member consultations."
General secretary Dr Peter Carter, said: "Throughout this process, our members' number one concern about pensions has been the prospect of working in a physically demanding job until the age of 68, which is due to take effect in 2046.
"The Government has acknowledged the physical demands of professions such as the police, who are not facing the prospect of working until they are nearly 70. We vehemently believe the demands of nursing mean that the same should apply to our profession and we are committed to stepping up campaigning on this issue to make the Government change its mind.
"It's clear when I listen to nurses from around the UK that the pressures facing them are immense, not just on the pensions issue but also the prospect of a massive NHS reorganisation, the threat of redundancy, a pay freeze and deteriorating staffing levels.
"Despite all this, nurses and healthcare assistants continue to put the interests of their patients first. That's why they were so dismayed when the Secretary of State for Health attributed our opposition to the Health and Social Care Bill to simple self-interest on the pensions issue. The anxieties of our members continue, and we will continue to speak up on their behalf."
Tens of thousands of civil servants have started voting on the next steps in the long-running row, which remains deadlocked despite Government attempts to reach a deal with unions.
More than 250,000 members of the Public and Commercial Services union are being asked if they reject the "final" offer on changes to public sector pensions and whether they support an ongoing campaign of opposition.
The PCS said it was talking to other unions with members in the public sector, including those representing health workers and teachers, with a view to taking coordinated industrial action on March 28.
More than one-and-a-half million workers staged a one-day strike last year, with doctors the latest group to be balloted for industrial action.
The PCS executive has unanimously rejected the Government's latest offer, saying it would force public servants to work up to eight years longer for a worse pension in retirement, and to pay more in contributions with the money going to the Treasury to pay off the budget deficit.
Health Secretary Andrew Lansley said: "It is disappointing that some RCN members have voted against the proposals.
"However, only 16% of RCN members voted. We know that some nurses are unsure what the proposals would mean for them - that is why we have set out the facts and published a calculator so that nurses can see for themselves whether or not their pension would change.
"Most nurses over 45 will not be affected by any changes. Everything people have already earned will be protected and most low and middle earners working a full career will receive pension benefits at least as good, if not better, than they get now.
"But change is necessary - people are living longer, healthier lives.
"Today, a nurse can expect to spend nearly 33 years in retirement - around nine years more than 30 years ago.
"The improved proposals, the main elements of which nearly all unions signed up to in December, are a fair deal for staff and taxpayers and make public service pensions affordable and sustainable. This means the nurses who dedicate their life to treating us will continue to receive pensions that are amongst the best available."