Thousands of health workers have massively rejected a three-year pay offer, setting themselves on a collision course with the Government and causing fresh problems for the Prime Minister.
The GMB, which represents 25,000 NHS staff in England and Wales, said its members voted against the three-year deal by more than 96%.
A separate ballot of ambulance workers showed an even bigger rejection - 97%.
Members of the GMB are the latest group of health workers to vote against the Government's offer of a deal worth just under 8% over three years.
The Royal College of Midwives said a consultation of its members showed a massive 99.7% rejection of the deal earlier this week.
GMB, which represents ambulance crews, porters, catering staff, ancillary workers, blood collection, nursing assistants and practitioners, cleaners, laboratory workers, drivers and maintenance staff, said it will now seek an immediate meeting with Health Secretary Alan Johnson.
Midwives and other NHS staff are supporting a one-year increase of 2.75%, which was recommended by a pay review body before the Government intervened to press for a longer deal.
Dame Karlene Davis, general secretary of the Royal College of Midwives (RCM), said earlier this week: "We have strongly argued that, given the outlook for the economy in future years, acceptance of the three-year deal would represent a vote for a real terms pay cut."
Leaders of the Royal College of Nursing are urging acceptance of the deal, but more than 500,000 members of Unison are being balloted without a recommendation.
Members of the union Unite, including porters, caterers and cleaners, have also rejected the deal by six to one.
