He was an unlikely guerrilla leader; a rather earnest, middle-aged, middle-class, suburban white man in a bush hat. Imagine Jeremy Corbyn as an extra in Out Of Africa.

I found him one hot afternoon in 2003, standing under an acacia tree in the remote Kenyan bush. At his feet sat a couple of hundred Samburu tribeswomen in traditional dress. Eight mixed race children had also been arranged about the visitor, rather like exhibits for a lecture. It soon became clear that is exactly what they were.

‘It is very sad how these children were brought into the world,’ the man told his audience. ‘But we want to make sure that people throughout the world know what the British Army has done here.’ The speaker was a London lawyer called Martyn Day. He had travelled to East Africa to do what in subsequent years has earned him a considerable professional reputation and no small income: trashing the good name of Britain’s Armed Forces.

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Labour leader Jeremy Corbyn, second left, pictured beside layer Martyn Day, left, who represented three elderly Kenyans in a court case where they claimed they had been abused by British troops during the 1950s

A few days earlier, Mr Day had informed a London press conference that 650 Kenyan women had been raped or gang-raped by British soldiers visiting the country on warm weather exercises over a period of almost 30 years. At least £20 million was to be sought by him for the victims in compensation — malipo in the local language. ‘It is almost as if the British Army could throw away its rule book when it came to Kenya,’ he said.

As we shall see, when it came to the claims of Mr Day, ‘Kenya’ would soon be substituted for the names of a number of other countries. And in each case, it was more malipo that he was seeking.

Nearly a decade later, in October 2012, Mr Day — as our picture reveals — stood shoulder to shoulder with Jeremy Corbyn, now of course the Labour leader, to witness three elderly Kenyans represented by Mr Day being granted permission to claim damages for abuse they said they suffered while imprisoned by the British during the anti-colonial Mau Mau rebellion.

That summer of 2003 when I met him at the small bush settlement of Archers Post, was a transformative time for Mr Day and another British human rights lawyer, Philip Shiner.

Ill-advisedly, Britain had just taken part in the invasion and occupation of Saddam Hussein’s Iraq. British forces were already in Afghanistan, and would eventually be given the bloody and unrealistic task of the pacification of the Taliban heartland of Helmand.

As those conflicts progressed, the atrocities that had allegedly been committed by British soldiers against African tribeswomen were to be dwarfed by the barbarisms our military would inflict on the Iraqi and Afghan civilians. Or so Messrs Day and Shiner would have the world believe.

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Phil Shiner, pictured, describes himself as a 'committed socialist' and received £3 million in legal fees for taking British soldiers and the Ministry of Defence to court over allegations of abuse by the British military

Both men headed their own law firms — Mr Day’s was called Leigh Day, and Mr Shiner’s Public Interest Lawyers (PIL). Yet over the past decade they have worked in tandem on thousands of individual cases of alleged abuse, torture and murder brought by foreign nationals against the British military, largely funded by British public money. Theirs is in effect a ‘Legal Aid insurgency’, as one old soldier described it to me, witheringly.

As the Mail revealed this week, the financial cost alone to Britain has been staggering.

Since 2003, the MoD has spent £100 million on Iraq War-related investigations and compensation. Another £44 million has been set aside for ongoing Iraqi compensation claims, of which there are still 2,360 outstanding.

A further £55.7 million has been ring-fenced for the Iraq Historic Allegations Team, which was set up by the MoD in 2010, to investigate similar cases up to 2019.

That team is now investigating 1,500 alleged victims of British military abuses, 280 of whom are alleged victims of unlawful killing by UK forces in Iraq. As the Mail reveals today, 300 soldiers have already received letters from an inquiry warning they face interrogation over ‘abuse’. Those men could potentially go on trial accused of war crimes.

Most of these cases have been handled by the firms run by Messrs Day and Shiner, and are funded by British taxpayers through Legal Aid. Mr Shiner’s PIL alone has received £3 m from the MoD for legal costs.

Conservative MP and former British Army Officer Colonel Bob Stewart, pictured, has condemned the lawyers describing them as 'ambulance chasers par excellence' for 'hounding our brave service personnel'

Afghanistan has not been forgotten either by these self-appointed crusaders for justice.

In October, the Royal Military Police began an investigation into 100 alleged cases of abuse against detained Taliban insurgents by British soldiers. Once again, the cases were brought to light by Leigh Day and PIL.

One must now expect the number of Afghan allegations against British soldiers to multiply, and civil claims for compensation to follow. It will be very expensive. And a good chunk of that will be claimed by the two law firms which have done so much to drag the military’s reputation through the mud.

A furious Bob Stewart, the Tory MP and former Army officer, last week called them ‘ambulance chasers par excellence’. Another Tory MP, Stewart Jackson, used parliamentary privilege to brand Leigh Day ‘immoral, thieving’ lawyers who, along with PIL, ‘specialise in hounding our brave service personnel with spurious claims’.

Yet while their own rewards are plainly not insignificant, there is perhaps an even stronger ideological motive for the solicitors’ zealous pursuit of the military establishment.

Mr Shiner wears his political colours on his sleeve. They rather match his pink designer glasses. Coventry-born and Birmingham-based Mr Shiner, a twice-married father of five and former altar boy who’s in his 60th year, is described as a ‘committed socialist’.

He worked for Labour MP Frank Field before setting up PIL, a not-for-profit company, in 1999. In 2006, he helped found the British Muslim Human Rights Centre and has represented the Campaign for Nuclear Disarmament. He lives in a pretty Edwardian avenue.

Mr Day secured permission to sue on behalf of Kenyans who claim they were brutalised by British troops during the Mau Mau insurgency in Keny during the 1950s, pictured

In an interview last summer, Mr Shiner seemed to liken Britain’s military to both that of Nazi Germany and President Assad’s Syria.

‘Look at us,’ he said. ‘We’re supposed to be . . . a great democratic state that abides by the rule of law. Now countries can turn around and say: “No you don’t — you’re not better than us.” The Syrian government can say: “Don’t you dare lecture us on what we would and should not be doing.” ’

The blame, he suggested, lay in Britain’s colonial past. ‘Nobody has ever made the British public face what their armed forces did in the Second World War and the colonial wars since,’ he says. ‘Germany was divided into four, made to eat humble pie, and national monuments were built commemorating their atrocities. What have we ever done? Nothing.’

Father-of-five Martyn Day, 57, who lives in a £2 million detached home in South-East London with second wife Carol, a solicitor who runs the Environmental Litigation Service at Leigh Day, is cut from a similar cloth.

He describes himself as a ‘bolshie b*****d’; so bolshie in fact that he was sacked from his first legal job, at a trades union law firm. He later called a strike over low pay at the famously Left-leaning Bindmans legal firm.

He founded Leigh Day with a Bindmans colleague in 1987. It is now Britain’s largest firm of criminal neglect lawyers — it specialises in environmentally related group actions against big corporations — and one of its biggest fans is Labour MP Emily Thornberry. She thinks it is ‘great’.

The feeling is mutual: Leigh Day paid the £14,500 it cost for Ms Thornberry to hire a legal research assistant for her office.

Leigh Day solicitors has paid £14,500 for Labour's new defence spokeswoman Emily Thornberry, pictured, as part of a total of £48,000 in donations to the politician who is opposed to the renewal of Trident submarines

In fact, Ms Thornberry has registered a series of donations worth £48,000 from Leigh Day, which is why last week the collective jaw of the military establishment dropped when Jeremy Corbyn made her his new Shadow Defence Secretary.

In other words, the woman who would be in charge of our Armed Forces — if Labour wins power — has taken tens of thousands from a firm which seems intent on ruining the reputation of the military.

But now Mr Day — and indeed Mr Shiner — have a more pressing matter to contemplate than any controversy about conflicts of interest on the Labour front bench. One day in May 2004, a unit of British forces in southern Iraq was ambushed by insurgents of the militia known as the Mahdi Army. There was a fierce firefight and many insurgent casualties.

It was subsequently alleged by a number of Iraqis that, after the battle, innocent civilian detainees had been tortured and murdered by enraged British soldiers. Victims and their families were represented by, yes, you’ve guessed it, Leigh Day and Public Interest Lawyers.

The so-called ‘Al-Sweady’ public inquiry into the allegations began in March 2013. The inquiry report was delivered in December 2014 and it was devastating for both PIL and Leigh Day. Among the conclusions were that the allegations of murders were ‘the product of deliberate lies, reckless speculation and ingrained hostility’ by Iraqi detainees. The inquiry had cost the taxpayer £31m — almost £1m of which went to PIL.

But there were other, even more troubling allegations than simply that vast amounts of money had been wasted. They were to be levelled against the law firms which pursued the murder and torture fantasy against British soldiers, some of whom later spoke of their anguish at being under suspicion for so long after simply doing their jobs in great peril.

The Al-Sweady public inquiry investigated allegations that British troops abused Iraqi detainees, pictured, but investigation found no evidence of ill-treatment claiming they were the 'product of deliberate lies'

Bob Ainsworth, the Labour MP who, as Defence Secretary had launched the initial investigation in 2009, was particularly exercised. He said: ‘I commissioned this report only after the [defence] department was very heavily criticised in the courts for having failed to investigate properly the allegations that were being made.

‘I believe then, as I believe now, that the main reason for that failure wasn’t a lack of will on our part but a refusal to co-operate with an inquiry by the representatives of the Iraqis, Public Interest Lawyers, and Mr Phil Shiner.

‘I have no way of knowing or proving what the motives were for that lack of co-operation, but I do know Public Interest Lawyers have a very lucrative business model.’

After the inquiry’s devastating findings, the Solicitors Regulation Authority (SRA) watchdog began an investigation into PIL and Leigh Day.

Shortly afterwards, the MoD submitted its own dossier of allegations against the firms to the SRA. The dossier reportedly called for Mr Shiner to be fined and struck off for misconduct, and alleged that his firm had known for 12 months before they admitted it that the murder and torture allegations could not be sustained by evidence.

The then Defence Secretary, Michael Fallon, said: ‘This was a shameful attempt to use our legal system to attack and falsely impugn our Armed Forces.’ The MoD dossier also accused PIL of using a local agent to tout for business in Iraq, in the southern city of Basra — a breach of the solicitors’ code of conduct. Hundreds of claims had flooded in within weeks.

Last week, the Mail revealed how while working with PIL, an Iraqi named Abu Jamal was also being paid up to £40,000 a year by the MoD to help the Iraq Historic Allegations Team inquiries by identifying and bringing alleged witnesses from Iraq to the relative safety of five-star hotels in Beirut, from which they would give statements to London by video link.

Nice work if you can get it. But what a mess it all is.

‘Bolshie b*****d’ Mr Day was very sorry for himself. He said: ‘Maybe the Iraqis were fantastic liars. It seems they hoodwinked us. Perhaps I am a s**t lawyer, but I stand by the fact that [the allegations] warranted an inquiry. We do high-profile cases. We make big enemies. When they get a chance, they have a go at us.’

And rightly so.

The various legal claims against the MOD are believed to have influenced the handling of the Alexander Blackman case

Mr Shiner was more bullish. He complained that he was being persecuted by a vengeful government; his life had been threatened.

The Haldane Society of Socialist Lawyers, of which he is an honorary vice-president — the President being Michael ‘Moneybags’ Mansfield QC — began an online petition calling for David Cameron to stop ‘intimidating’ lawyers.

On Wednesday last week, it was announced that the SRA was referring Leigh Day and a number of its solicitors to the independent Solicitors Disciplinary Tribunal, the legal profession prosecutor. It is not known if Mr Day is one of them.

If found guilty, the lawyers could be struck off.

During the Al-Sweady inquiry into the allegations of war crimes in Iraq, it had emerged that Leigh Day had destroyed a key document that appeared to show Iraqi claimants were armed insurgents, not innocent farmers. It was given to the firm in 2007 and made public in 2013. But the day before it was due to be handed to the inquiry, a Leigh Day solicitor shredded it.

Asked in an interview about the allegations against Leigh Day, the new shadow Defence Secretary Emily Thornberry, who took £48,000 from the firm and was pictured at a champagne-fuelled Christmas party with Martyn Day, said: ‘I have no idea what has happened or what these allegations are. I understand that they are currently before a solicitors’ disciplinary tribunal or something.’

She added: ‘It is not for lawyers to decide [if their clients are telling the truth], it is for the courts to decide.’

For their part, Leigh Day said: ‘The great majority of that work is undertaken on a no win, no fee basis — it is therefore absolutely in our interest only to bring viable claims, on behalf of our clients, to court.

‘Most of the actions we bring succeed. On some occasions they do not, demonstrating a properly functioning justice system.’

For a decade, Messrs Day and Shiner have had the MoD chasing its own tail. The effect of their actions on military morale and the military’s international image has been catastrophic; a comfort to Britain’s enemies.

I believe it also contributed towards the unjust manner in which the military handled the case of Royal Marine Sergeant Alexander Blackman, jailed for ten years for murder for shooting a mortally wounded Taliban fighter; no manslaughter verdict was offered him and our investigations suggested colleagues were discouraged from giving evidence. An expedient example was made, at Blackman’s cost. Of course every army, like any large organisation, will have ‘bad apples’. And they are bad apples with guns.

But the huge number of atrocities alleged by Day and Shiner to have been committed by our troops in Africa, the Middle East and Central Asia gave the ludicrous impression that our military was both morally bankrupt and out of control.

Alas, the prospect of compensation can persuade poor people to make up all kinds of stories.

The number of Kenyan women who alleged to Mr Day’s team that they had been raped by British soldiers would eventually soar to 2,187. And all the while, Mr Day alleged, the MoD knew, yet had done nothing.

Some women who claimed to have been raped by British troops during the Mau Mau uprising later admitted they had been coached by a Kenyan human rights organisation about their stories of abuse

Standing under that tree in Kenya in 2003, I heard him tell the Samburu women: ‘Last week, Amnesty International published a report that found the rape allegations to be totally true. The same day, we received confirmation from the British Legal Aid authorities that they would fund your case through the courts.’

The children at his feet would soon be taken to London so that the world could view what were said to be the blameless fruits of Britannia’s shame.

How his audience cheered. And, quite possibly, began to imagine how they, too, could get their hands on a slice of the malipo.

Very soon afterwards, however, his claims and case began to unravel.

Women who had claimed rape admitted that they were coached by activists from a Kenyan human rights organisation. Police records of alleged historic offences were found to be forged. Some of the British Army units accused were not even in Kenya at the time. Many of the mixed race children were the products of consensual sexual relationships with tourists and white locals.

In 2006, a Royal Military Police investigation concluded that while not all claims were bogus, there was no ‘reliable evidence to support any single allegation which would stand up (beyond reasonable doubt in a criminal court)’.

Mr Day had to admit that some of his clients had lied.

Both Leigh Day and Public Interest Lawyers deny they have committed any wrongdoing or breach of legal regulations. Now, that is for the Solicitors Regulation Authority or the tribunal to decide.