Paramedics are set for pay rises worth at least £4,400 from the Department of Health and NHS Employers amid trade unions’ concerns that their members were not being paid properly for their life-saving work.

About 12,000 of the health workers – who are trained in emergency medical care and first aid, but not to the level of a qualified doctor – will be affected by the agreement, which will increase starting salaries from £21,909 to £26,302.

Under the terms of the deal, most paramedics, including ambulance crews, will move up the pay scale. However, union leaders have warned that the change may not be enough to staunch a steady drain of workers leaving the ambulance service.

While Christina McAnea, the Unison union’s head of health, backed the new pay deal, she added: “The banding issue alone may not solve the drain of paramedics from the ambulance service, but it will certainly make it a little easier for trusts to hold on to experienced staff.”

The pay rise comes as the UK faces a critical shortage of paramedics, which has left at least one trust paying £30 an hour for agency staff – almost double the rate given to staff workers – and another seeking permission from immigration officials to poach 250 workers from Australia and New Zealand.

Paramedics have reported working under tremendous pressure as a result of increasing demand and a healthcare system battered by cuts. Many say they continue working well past the end of their 12-hour shifts, and rarely get meal breaks. At the end of 2015, a survey of 3,200 paramedics, commissioned by the GMB, Unison and Unite unions, found that three-quarters said they were planning to quit the NHS.

The DoH said the deal had been the result of several years’ negotiation between government officials and unions to thrash out how best to recruit and retain ambulance staff. It goes hand in hand with plans to modernise the role of paramedics, including expectations that they will carry out more treatment at the scene of emergencies, and take patients to medical centres other than hospitals, a spokesman said.

He added that 2,200 more paramedics had been recruited since 2010, and the number of training contracts had been increased by 60%.

Jeremy Hunt, the health secretary, said: “In recognition of their increased responsibilities, we have agreed to look at rebanding around 12,000 paramedics where their job description matches the requirements of the new band six profile, moving them up the pay scale and making sure we are able to better recruit and retain paramedics in the future to ensure patients will continue to get the very best care.”

Sharon Holder, national officer of the GMB general trade union, said: “GMB has campaigned for many years to ensure all ambulance staff receive fair pay. This agreement is a step in the right direction.

“The GMB is pleased the Department of Health has finally realised paramedics need to be paid properly.”