The Government's planned cuts to legal aid in clinical negligence cases could cost the NHS almost three times more than is saved by the Ministry of Justice, a report said today.
While official estimates predicted savings of £10.5 million, knock-on costs of some £28.6 million, mostly borne by the NHS, had not been accounted for, the report by King's College London found.
Justice Secretary Kenneth Clarke has said legal aid is facing an "existential crisis" and must be streamlined to survive.
It was "neither affordable nor sensible" to have a system that operated like the NHS by providing "for any need", he said last month.
The report, commissioned by the Law Society, found that overall the reforms could lead to knock-on costs of more than £130 million.
It said the proposed reforms, which have already been delayed for six months, would save just £100 million, less than half predicted in the official impact assessment.
The report, which comes as the Government's Legal Aid, Sentencing and Punishment of Offenders Bill is expected to face fierce opposition in the Lords, said the reforms were "unlikely to make a significant contribution to reducing the fiscal deficit".
It looked at three key areas of legal aid - clinical negligence, private family law, and social welfare.
It found that in clinical negligence cases, the Bill would "generate a net loss of approximately £18 million per annum for the Government which would largely be borne by the NHS through the NHS Litigation Authority."
Social welfare cases, such as those which relate to physical and mental health, would lead to knock-on costs of £35 million and private family law cases would lead to knock-on costs of £100 million, set against a predicted £170 million saving.
Desmond Hudson, chief executive of the Law Society, accused the Ministry of Justice of "kamikaze accounting".
"The Ministry of Justice has defended swingeing cuts to legal aid in civil cases, which will deny justice to thousands, on its need to contribute savings to the Government's deficit reduction programme," he said.
"The Law Society accepts the need to achieve savings, but this report confirms that much of the Ministry of Justice's claimed savings are being achieved at the expense of other parts of Government.
"This is kamikaze accounting and will do little to tackle the deficit while sacrificing access to justice. Should we be promoting our justice system internationally while denying access to ordinary citizens?"
He went on: "It is time for the Government to work with the Law Society and other groups to radically reshape this Bill."
The analysis comes after lawyers warned that Government plans to focus so heavily on mediation when couples separate will punish those with abusive or unco-operative partners.
Resolution, which represents 6,000 family lawyers and professionals, said mediation could be inappropriate in as many as two in five cases.
Justice Minister Jonathan Djanogly has said the the process of separation and decisions about future arrangements for children could be made simpler if families chose mediation.
But this would have been unsuitable in 5,416 of the 13,315 legal aid cases (41%) involving the association's members, Resolution said.
Under the planned reforms, 600,000 people will no longer receive legal aid, 68,000 children will be affected by the removal of legal aid in family cases, 54,000 fewer people will be represented in the family courts annually and 75% of existing private family law cases will no longer attract legal aid, campaigners have said.
Measures being introduced in the Bill would also see more people going to court on their own without legal representation, a move senior judges have warned could increase both costs and delays.