The Victoria Cross won by one of 'Britain's bravest soldiers' who was mortally wounded by friendly fire while waist deep in a flooded trench is tipped to sell for £250,000.

Lieutenant Colonel Bertram Best-Dunkley was a survivor of both the Somme and the first mustard gas attack in the First World War at Ypres.

His fateful heroics in the hell of the Battle of Passchendaele came just days after his wife gave birth to the baby son he never got to meet.

On July 30, 1917 at Pilckem Ridge in Belgium he watched as dozens of men and officers were cut down by enemy machine gun fire from positions believed to have been in British hands.

Realising all of the officers in the advance had been knocked out, Lt Col Best-Dunkley stepped forward to lead what was left of the unit into the murderous onslaught.

Not only did he and the men retake the positions, they launched a successful attack on the German lines.

The next day, he commanded his unit in repelling a fierce German counter attack from a trench filled with rain water.

It was against the hellish backdrop of bodies of men and horses strewn across the muddy and flooded battlefield Lt Col Best-Dunkley was struck by a shell from a British gun that fell short of its target.

Although he survived the impact and was taken to a hospital clearing station he died from his wounds five days later.

On his deathbed, he told the battalion padre how he hoped his general was not too disappointed with his efforts.

A note of reply came back from Major General Hugh Jeudwine which read: 'Disappointed? Indeed, I am more proud of having you and your battalion under my command than anything that has ever happened to me.

'It was a magnificent fight, and your officers and men behaved splendidly, fighting with their heads as with the most superb pluck and determination.'

At his burial service, the Maj Gen Jeudwine said: 'We are burying one of Britain's