The government intends to put strict limits on the "excessive fees" some lawyers claim in medical negligence cases against the NHS in England.
Officials want a defined limit on legal costs in cases where the claims are below £100,000, saying that some lawyers submit bills that charge more than patients receive in compensation.
But solicitors warn the move could deny patients access to justice.
Figures show the NHS was charged £259m in legal fees for claims in 2013-14.
The NHS did recoup £74m by challenging some claims made in 2013-14, but the Department of Health says taking these cases to court is costly and time-consuming and believes further savings could be made.
Officials say their proposals, which will be open to public consultation in the autumn, would ensure lawyer's fees are more proportionate and reflect the amount of compensation patients receive
They give as an example once case where a patient received £11,800 in damages but the legal fees, which the NHS had to recompense, totalled £175,000.
Health Minister, Ben Gummer, said: "Safe, compassionate care is my upmost priority and to achieve this, the NHS must make sure every penny counts.
"Unscrupulously, some lawyers have used patient claims to load grossly excessive costs onto the NHS and charge far more than the patient receives in compensation."
But a leading clinical negligence solicitor, Terry Donovan from the law firm Kingsley Napley, said costs are sometimes driven up by delays in the NHS admitting liability.
He added: "This sounds like another massive attack on access to justice for everybody.
"Fees are already tightly controlled, with the courts managing costs carefully as a result of recent reforms. Costs are already capped and limited.
"These so-called low value cases under £100,000 still involve cases where people have had serious injuries and lives have been destroyed.
"Costs can be very proportionate if the NHS will admit liability promptly when it's appropriate.
"But defendants drive up costs if they don't admit liability early on and the case ends up in court."
Meanwhile, the Medical Defence Union, which offers doctors guidance on medico-legal issues, supported the move.
Dr Matthew Lee, professional services director for the MDU, said: "Patients often need to meet part or all of these costs themselves but the system must provide access to justice where patients have been negligently harmed.
"Legal fees must, therefore, be affordable and proportionate.
"If it was decided to introduce a well-thought-out, fixed-cost structure for legal costs in clinical negligence claims that could only be a good thing and should result in legal fees becoming more affordable and proportionate to the compensation claimed by the patient."