Legislation hailed by defence ministers as being a way to end repeated investigations against military personnel is "not fit for purpose", according to a cross-party group of MPs.
The Joint Committee on Human Rights has released a damning report which concludes that while the Overseas Operations Bill offers hope, it does nothing to solve the problems it is aimed at addressing.
The group is urging the Government to reassess the proposed legislation before pushing forward.
Committee chair and senior Labour MP Harriet Harman told Forces News that the problem is not with the prosecution side of the justice system, but the initial investigations process.
"What needs to happen in order to stop repeated investigations is that the first investigation needs to be a good one; a forensic one; a deep one; one that can command confidence," Ms Harman said.
"If you have a partial investigation that doesn’t interview the right people, that doesn’t look through logs, then what happens is you leave a vacuum and inevitably there will be another investigation which is not fair on the victim and is not fair on the alleged perpetrator either."
The Overseas Operations Bill would introduce a presumption against prosecution of personnel after five years, time limits on bringing civil claims in connection with overseas operations, and the potential to derogate from the European Convention on Human Rights.
The Committee criticised the changes, concluding that they would not only introduce further barriers to providing justice for victims, but also risk preventing prosecutions for serious offences such as torture, war crimes and genocide.
They also questioned ministers' use of the term 'vexatious' when talking about investigations.
Of 27 prosecutions brought against personnel since 2000, only eight ended in convictions, with the Committee saying it found no evidence of any of those being 'vexatious'.
MPs believe incorrect use of the term 'vexatious' shows a failure to respect the role and rule of law.
Elie Cumbo, Head of Public Law at The Law Society agrees.
"Undoubtedly, it has the effect of setting the justice system and legal professionals up as if they had a particular agenda... as though they were trying to make life difficult for either the Ministry of Defence or for service personnel themselves," she told Forces News.
"Before you come on to the solutions, there does need to be some evidence base, which hasn't yet been provided, that there are either too many prosecutions being brought or too many civil claims being brought or that they are largely lacking in merit, which doesn't seem to be the case when you actually look at the statistics."
In a statement, Minister for Defence People and Veterans Johnny Mercer said: "I came into politics to help ensure our Armed Forces living under the shadow of seemingly endless investigations were given stronger legal protections in the face of vexatious claims.
"It is untrue to suggest this bill will prevent crimes from being prosecuted or stop the MOD from being held to account for wrongdoing.
"Military operations will continue to be governed by International Humanitarian Law, including the Geneva Conventions, and this vital piece of legislation will help protect military personnel and veterans from vexatious claims and the cycle of re-investigations.
"Torture is not being decriminalised.
"I thank the Joint Committee on Human Rights for compiling their report.
"We will consider their findings and respond in due course."
The Overseas Operations Bill is due to have its third reading in the Commons on Tuesday.
Harriet Harman says the Government still has time to ask if it is doing the right thing telling Forces News: "It's better to stop late in the day than go ahead with something that is just wrong."