THE prominent role of former Thurrock MP Andrew Mackinlay in a 16 year campaign that ultimately led to a pardon for more than 306 British and Commonwealth soldiers executed in World War One is told in a new book.

Mr Mackinlay, 71, who served as Thurrock's MP from 1992 until he stepped down at the 2010 general election, took the cause of the men who were 'shot at dawn' to his heart and led from the front in Parliament, championing the particular cause of Harry Farr.

Farr, who had served through the first two years of the war on the Western Front including the battle of the Somme, was executed for cowardice at the age of 25.

He had been returned to the front lines after being hospitalized after the position he was in was heavily shelled during 1915. He had suffered convulsions and collapsed and was undoubtedly suffered from what is now known as shell shock. It is also thought he was suffering from hyperacusis, which occurs when the inner ear is damaged, causing it to lose its ability to soften and filter sound, making loud noises physically unbearable.

On 22 July 1916 he spent the night at a medical station and was discharged for duty the following morning.

On 17 September 1916 he again attempted to seek the help of a medical orderly, but was refused as he was not physically wounded and the aid station was dealing with a high number of battle casualties. Farr reported for duty at the transport lines at 8pm that evening, but went missing shortly afterwards.

Upon being found at 11pm he refused to return to the front line. He was subsequently arrested for disobeying orders, and on 1 October 1916 tried by court martial. He had to defend himself against the formal accusation of 'misbehaving before the enemy in such a manner as to show cowardice'.

The Divisional court martial, presided over by Lieutenant-Colonel Frederick Spring, the Commanding Officer of the 11th (Service) Battalion of the Essex Regiment, lasted 20 minutes, and many questions have subsequently been raised about its competence. The hearing found Farr guilty and sentenced him to death.

Harry Farr met his death at the hands of a firing squad made up of his regimental comrades on 18 October 1916, near Carnoy on the Somme.

There are many, many similar stories and they have been catalogued in an earlier book by David Johnson 'Executed at Dawn: British Firing Squads on the Western Front 1914-18.' Mr Johnson has now followed it up with a new book 'The Last Campaign of World War One (1990 – 2006) which tells the story of the Shot at Dawn Campaign to obtain pardons for those 306 soldiers who were executed and the establishment's efforts to thwart it.

Mr Mackinlay's interest in the campaign began in the same year as he was elected. Taking a break after winning his seat he visited Ypres, where the Menin Gate stands as testimony to the tens of thousands of men who lost their lives and had no known grave. He also visited the Tyne Cot cemetery where 11,965 men lie - 8,369 who are unnamed.

It was in those sombre moments and after a visit to Poperinge, a behind the lines village where many British soldiers were executed, that Mr Mackinlay began to take an interest in the campaign.

Mr Mackinlay, who now lives in Kington on Thames in retirement, believed that as an MP he was in a position to do something to support the then fledgling campaign for a pardon for those executed and he tabled an early day motion which stated "it is not too late to restore the names and reputations pf the 306 soldiers of the British empire Forces court martialed and executed mostly on the Western Front in the four years 1914-18".

The motion did not succeed – it gained the support of just 67 fellow MPs, but it laid down a marker for a the political battle that would ultimately end in success more than a decade later!

During the campaign Mr Mackinlay came to know Gertrude, Harry Farr's wife and he met many other families of those shot at dawn who believed their relatives' deaths were totally unjust.

Among the many stories similar to Mr Farr's there are some shocking revelations, not least that of the first soldier to die strapped to a stake, fired on by his comrades.

Private Thomas Highgate was the first to suffer such military justice. Unable to bear the carnage of 7,800 British troops at the Battle of Mons, he had fled and hidden in a barn. He was undefended at his trial because all his comrades from the Royal West Kents had been killed, injured or captured. Just 35 days into the war, Private Highgate was executed at the age of 17.

Many similar stories followed, among them that of 16-year-old Herbert Burden, who had lied that he was two years older so he could join the Northumberland Fusiliers. Ten months later, he was court-martialled for fleeing after seeing his friends massacred at the battlefield of Bellwarde Ridge. He faced the firing squad still officially too young to be in his regiment.

Those stories inspired Mr Mackinlay and others to campaign on for a pardon, despite many disappointments and let-downs from senior politicians, including Prime Minister John Major. They met with passionate opposition from the Ministry of Defence and some MPS, including Anne Widdicombe who described the granting of pardons as 'the lazy and the cowardly way out'.

However, on 8 November 2006 an amendment to the armed Forces act was passed. It conditionally 'pardoned the men of the British and Commonwealth Forces who were executed in the First World War.

In his book, David Johnson writes: "Clearly a posthumous pardon wouldn't bring back the men who had been executed, the families they might have had, or their achievements but it clearly mattered to the surviving family members and to the wider population.

It clearly mattered to Mr Mackinlay too. His role in the campaign was praised in the House of Commons by Conservative MP Gerald Howarth who said: "No one has done more than the hon. Member for Thurrock in bringing the issue before the House, as he has done persistently and tenaciously. I suspect that in the fullness of time this will come to be know as the Mackinlay amendment."

Other suggested that there might be official recognition, including Mr Johnson whose final thought in the book was: "Whatever you might think of the country's honours system, it seems strange that none of those that led and took part in the Shot at Dawn campaign have ever received an honour for what they did. This could perhaps be viewed as a last churlish response by the Establishment, given that the campaign was, at its heart anti-Establishment, as many of those who opposed the granting of the pardons have since been, for example, elevated to the House of Lords.

"Almost certainly, because for the Ministry of Defence it had been a humiliating capitulation and so if the question of honours ever came up then the Ministry would in all likelihood veto such a move."

In July 2009 Andrew Mackinlay announced that he would not stand in the next general election due to disillusionment with the way he felt other MPs had caved in to party pressure rather than standing up for their beliefs. The final straw was the failure of a number of Labour MPs who had expressed support for Gary McKinnon, awaiting extradition to the USA on computer hacking charges, to vote for a review of the extradition treaty.

• The story of Harry Farr is told in a book 'He Was No Coward: The Harry Farr Story' by Janet Booth and James White.