The UK's veterans minister has blasted 'deeply disingenuous' MPs for rebelling against his bill aiming to protect members of the armed forces from historical prosecutions.
Johnny Mercer has accused fellow politicians of 'repeating campaign lines they know to be untrue' over his Overseas Operations Bill.
The MP, a former Army officer who did three tours of Afghanistan, says his bill will help protect armed forces personnel against 'vexatious claims' and 'repeated historic investigations' long after they have served.
It comes after British officer Major Robert Campbell was cleared for the eighth time, and after 17 years, over the death of an Iraqi teenager.
Mr Mercer says his bill will raise the threshold for criminal prosecutions after five years - switching it to a presumption against prosecution.
Johnny Mercer (pictured left) has accused fellow politicians of 'repeating campaign lines they know to be untrue' over his controversial Overseas Operations Bill. The row over the bill comes after British officer Major Robert Campbell (pictured right) was cleared for the eighth time, and after 17 years, over the death of an Iraqi teenager.
Mr Mercer, a Tory MP and former Army officer who did three tours of Afghanistan, says his bill will help protect armed forces personnel against 'vexatious claims' and 'repeated historic investigations' long after they have serve
But the bill has stirred debate among politicians, after a warning by the Joint Committee on Human Rights (JCHR) that veterans could escape justice for offences such as torture.
MPs David Davis, a former Tory cabinet minister who served in the territorial SAS, and Dan Jarvis, a Labour MP who served as a paratrooper in Kosovo, Iraq and Afghanistan, are spearheading a move to alter the bill - which returns to the Commons at report stage tomorrow.
But, ahead of the reading, Mr Mercer today took to Twitter to hit out at politicians attempting to amend the bill.
In a post, he said: 'Working on this bill has been an abject lesson for me.
'Deeply disingenuous colleagues repeating campaign lines; talking a good game on standing up for our people, but fundamentally unwilling to lift a finger to do anything about it.'
In a follow-up post, in which he shared a joint article by Mr Davis and Mr Jarvis from the Times, he said: 'They either don't understand the fundamentals of the issue or wilfully conflate claims with investigations. Either are poor.'
He then added: 'The crowning t*rd in the water pipe is that Maj Bob Campbell, under investigation for 17 years before being cleared, who they cite, actually pleaded with one of these MPs to help him as a veteran in his dark days.
'He ignored him back then. Cites him today. Irony is dead.'
Ministers say the Overseas Operations Bill will limit false and historical allegations arising from overseas operations by introducing a statutory presumption against prosecution after five years.
This will make it exceptional for personnel to be prosecuted five years or more after an incident.
Ministers hope it will end the relentless 'vexatious' legal probes which soldiers have faced for more than ten years after serving in Iraq and Afghanistan.
But campaigners and some senior military figures have warned the legislation will create a presumption against prosecution of torture and other serious crimes except rape and sexual violence.
MPs have called for the bill to be amended so the presumption against prosecution does not apply to torture, war crimes, crimes against humanity or genocide.
However, over the weekend, Mr Mercer wrote to MPs insisting the bill 'continues to be misinterpreted', according to the Sunday Telegraph.
In the letter, seen by the paper, Mr Mercer said: 'This Bill is about protecting our Service personnel from the threat of vexatious claims and repeated investigations many years after they have served this country on overseas operations.'
Mr Mercer also said that the time scale for criminal prosecutions 'simply means that cases against Service personnel must be exceptional'.
He added: 'While the Bill does not directly stop re-investigations, in line with our national and international legal commitments, credible allegations will always be investigated, over time, we anticipate the police working closely with prosecutors early in the process to determine whether investigations should be reopened or continued.'
Despite Mr Mercer's defence over the weekend, writing a joint article in the Times today, both Mr Davis and Mr Jarvis criticised parts of the bill.
Writing a joint article in the Times today, both Mr Davis (pictured left) and Mr Jarvis (pictured right) criticised parts of the Overseas Operations bill
In their article, which Mr Mercer shared on Twitter as part of his criticism, they said: 'The defence minister, Johnny Mercer, has said the bill will end the vexatious claims against serving and former military personnel.
'The bill does nothing of the sort, and the joint committee on human rights rightly noted this week that it in fact does “nothing to address the issue of repeated investigations”.'
Meanwhile, The Times also reports that Andrew Mitchell, Ian Liddell-Grainger and Crispin Blunt, all Tory MPs who served in the military, have signed the amendment to the bill.
The paper reports the bill has also received cross-party backing from Ed Davey, the Lib Dem leader, Harriet Harman of Labour and Caroline Lucas of the Greens.
The row over the bill comes after former major in the Royal Engineers Robert Campbell was cleared for an eighth time over the death of an Iraqi teenager in 2003.
He was cleared of wrongdoing after a three-year investigation by a Ministry of Defence quango, the Iraq Fatality Investigations unit [IFI], following the death of 19-year-old suspected looter Said Shabram.