The "staggering sum" being paid out by the NHS as compensation in clinical negligence claims is "unsustainable", the Justice Secretary has been warned.
Health service leaders say the rising cost of payments to patients who have been the victim of medical errors is "already having an impact on what the NHS can provide".
The leaders of the NHS Confederation, the British Medical Association and the Academy of Medical Royal Colleges have written to Lord Chancellor and Justice Secretary David Gauke urging him to bring in reforms to the legal system "as quickly as possible".
The letter states: "The rising cost of clinical negligence is unsustainable and means that vast amounts of resource which could be used more effectively have to be diverted elsewhere."
It adds: "We fully accept that there must be reasonable compensation for patients harmed through clinical negligence, but this needs to be balanced against society's ability to pay.
"This is money that could be spent on frontline care. Given the wider pressures on the healthcare system, the rising cost of clinical negligence is already having an impact on what the NHS can provide."
The chairman of the Family Doctor Association, and the chief executives of the Medical Protection Society, Medical Defence Union and Medical and Dental Defence Union of Scotland, have also signed the letter.
The health leaders say the NHS in England spent £1.7 billion on clinical negligence claims last year - which represented 1.5% of spending on front-line health services - and say the figure has almost doubled since 2010/11.
The estimated total liabilities of the scheme in England were £65 billion for the financial year 2016/7, they said, adding: "This staggering sum is to pay for clinical negligence costs both this year and in future, which relate to claims arising from incidents that have already happened."
Writing in the Daily Telegraph, Niall Dickson, the chief executive of NHS Confederation, said it would take 13 years - and every penny of the extra Brexit money Boris Johnson demanded for the NHS - to pay off the current liability.
He added that a change to the rate at which damages in personal injury cases are worked out had had the "disastrous effect" of further inflating payouts, and said "fundamental reform" was needed.
The Ministry of Justice says it has put forward plans to help make the system fairer.
A spokesman said: "All personal injury victims should of course be fully compensated, but the costs involved should also be proportionate.
"To help ensure this happens, we have set out proposals for a fairer way of setting the personal injury discount rate, as well as asking the Civil Justice Council to look at measures to control costs in clinical negligence cases."