An "arbitrary" straitjacket on the NHS's budget by Whitehall is leading to job losses, recruitment freezes and inadequate care for patients, the leader of the country's doctors warns on Tuesday.

Dr Mark Porter, chairman of the British Medical Association, said forcing the NHS in England to make £20bn of "efficiency gains" by 2015 at a time of rising demand for healthcare was wrong and damaging.

Porter was speaking to the Guardian after the Department of Health (DH) admitted that 7,060 NHS clinical staff, such as doctors and nurses, have been made redundant since the coalition took power in 2010, at the same time as David Cameron was pledging to protect the service's frontline from cuts.

Responding to a freedom of information request, the DH disclosed that 4,620 frontline staff were made compulsorily redundant between 2010-11 and 2012-13, and a further 2,430 voluntarily redundant.

Labour, which obtained the DH's response, said it did not specify how many of each type of staff were made redundant. But the 7,060 total does include doctors, nurses, midwives, health visitors, ambulance staff and qualified scientific, therapeutic and technical staff, the DH said.

"The key thing to remember is that there's effectively a policy that results in redundancies because the single most important policy determinant in the NHS is the spending limits on it imposed by the government", Porter said.

"This is resulting in frontline redundancies and also in a widespread recruitment freeze. Some people are being made redundant but other posts aren't being filled. A significant number of [NHS] trusts are imposing a complete recruitment freeze," he added. The inability to hire new staff is "caused by the same driver as these redundancies, the Nicholson Challenge", Porter said, referring to the £20bn savings drive named after NHS chief executive Sir David Nicholson, which began in 2011. "Certainly the way it's working out some people are losing their jobs as a result."

The NHS's budget should be based on population growth and people's health needs "rather than arbitrary Treasury spending limits. The result of having a ringfence [around the NHS's budget] is widespread spending cuts across the NHS, which are being made at a time when need is increasing. That should cause us to stop and re-examine what's more important here. Are Treasury spending limits the best way to proceed? I think not."

Porter voiced concern that, despite several major reviews of NHS care and safety by Robert Francis QC and the service's medical director, Professor Sir Bruce Keogh, having emphasised the link between inadequate staffing and lapses in care, redundancies and recruitment freezes were undermining that.

Andrew Gwynne, the shadow health minister, said the 7,060 redundancies were "devastating for David Cameron. They reveal the hollow truth behind his pledge to protect the NHS frontline. Despite all the warnings on the need for safe staffing levels, ministers made experienced doctors and nurses redundant."

However, the DH pointed out that official figures show that there are nearly 7,700 more clinical staff working in the NHS than in May 2010. Renewed focus on care standards in the wake of Francis's report into the Mid Staffordshire scandal, and widespread demands for "safe staffing" levels, have forced many hospital trusts to take on extra personnel in recent months, especially nurses, even though their budgets are under pressure.

Some 2,740 of the 7,060 redundancies occured in 2011-12, the first year of the Nicholson Challenge, and a further 2,420 the year after. The DH said that £10.8bn of the £20bn target had been achieved by halfway point in April this year.

Labour also released a ministerial response to a parliamentary question which showed that a total of 7,435 fewer training places for nurses have been commissioned by the NHS in England over the last three years compared with 2009-10, when they were in power. In that year there were 20,829 training places available for would-be nurses, but that fell to 20,092 in 2010-11, then 17,741 in 2011-12 and then 17,219 in 2012-13.

Dr Peter Carter, chief executive of the Royal College of Nursing, welcomed a recent 9% agreed increase in nurse training numbers after staffing levels had become "eroded as a result of short-sighted attempts to save money". But, he added: "The NHS still has a mountain to climb in undoing the cuts that have already been made. In particular, we are concerned that some highly skilled specialists may be disproportionately targeted for cuts. The importance of safe staffing levels must be accepted throughout the NHS, and local organisations must be properly resourced to make them a reality for every patient."

From next April all trusts will have to publish details every month of how many nurses have been on duty in each ward, with patients able to see at a glance if expected new guidelines on minimum staffing levels have been met, as part of a raft of changes to improve care and openness following Mid Staffs.

The NHS in England employs more than 1.35 million people.