According to the Conservative Party, the NHS is set to fork out £713m in compensation for clinical negligence next year.
This year the NHS's bill is£396m meaning the amount will nearly double and is expected to take up a third of the extra funding hospitals have been allocated.
Shadow health minister Mark Simmonds described the system as "inefficient" and said it resulted in "vast legal costs" for the NHS.
The Conservatives said extra maternity funding from the Government is likely to be spent on increased premiums for negligence claims, which in that department alone is expected to be£119m.
Mr Simmonds said: "We need a robust and fair way for patients who have received negligent treatment in an NHS hospital to get the compensation they deserve.
"Instead, we have an inefficient system which incurs vast legal costs for NHS Trusts involved in legal battles."
A Department of Health spokesman admitted 2010's cost was "substantially higher" than previous years and said this was down to delayed settlements of more than 100 high-value cases.
He added: "The anticipated increase in clinical negligence payments for 2009/10 has been fully funded."
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