Jeremy Hunt's £1 billion pension giveaway to the richest 1% will stop just 100 hospital doctors retiring early per year, government data suggests.
The Chancellor's decision was branded a "pensions bung to the wealthy" with no evidence to justify it.
Mr Hunt claimed his decision to scrap the top limit on tax-free pension savings would keep high-earning NHS medics in work for longer. He said many were leaving to avoid taxes of up to 55% once their pension pots hit £1.07 million.
But just four months ago Health Minister Will Quince admitted the Government knew of only 105 senior doctors who had taken voluntary early retirement in the previous year - out of 20,218 who left the health service.
Thousands of fat cat bosses in the private sector will benefit from Mr Hunt's blanket decision to scrap the limit, which a leading think-tank estimates will cost the Treasury £1.2 billion.
Tax expert Prof Richard Murphy, of the University of Sheffield, told The Mirror: "If they don't know how many doctors are retiring for this reason, why did they change the pension policy for everybody to keep 105 doctors in the NHS?
"It looks like they used the fact that they know doctors are leaving for this reason to provide a pensions bung to the wealthy."
He continued: "They haven't got an evidence base for this policy, and that's good enough to say it can't have been for retiring NHS doctors.
"There isn't any evidence to support the policy."
Nearly 9,000 doctors did not give a reason for leaving, according to an answer given by Mr Quince to Shadow Health Secretary Wes Streeting in November.
Groups representing senior doctors, such as the British Medical Association (BMA), have lobbied for pension limits to be scrapped, but Labour said any changes should be "tailor-made" to medics.
Last week it vowed to reverse Mr Hunt's decision.
Lib Dem health spokesperson Daisy Cooper said: “After years of driving our health services into the ground, our NHS has lost far too many staff due to burnout or better pay elsewhere.
“Sadly, this move on its own does nothing for nurses, health care professionals and other dedicated NHS staff on low pay, who have been working to exhaustion in crumbling hospitals.
“The government needs to properly invest in our NHS and social care rather than taking a piecemeal approach.”
Think-tank the Resolution Foundation said most of those who benefit would be in the private sector, and said scrapping the limit on tax-free pensions savings "does not appear to be justified". It said the cost would be around £1.2 billion.
The annual tax-free pension pot allowance was raised to £60,000 from £40,000 in Mr Hunt's Budget.
A Department of Health and Social Care spokesperson said: “Estimates suggest 22,000 senior NHS clinicians could exceed the previous £40,000 annual allowance in 2023/24, and that around 31,000 clinicians had reached at least 75% of the £1.073 million lifetime allowance.
“The increase of the annual allowance to £60,000 and the abolition of the lifetime allowance will offer annual tax-free pension savings and unlimited pension savings over a full career.
“These measures will also ensure that NHS doctors are not discouraged from remaining in their roles and taking on extra hours – allowing them to treat as many patients as possible and tackle the backlogs.”
Shadow Chancellor Rachel Reeves said after the measure was announced: “A hand-out for the richest one per cent and their pension pots shows how out of touch this government is.
“Instead of boosting growth and helping ordinary working people with taxes, this is the choice they make. Outrageous.”
