Their numbers have dwindled to fewer than a dozen but as they prepare to mark both Armistice Day and Remembrance Sunday their spirit and pride is unfaltering.

Most of the remaining veterans of the First World War are now too old and weak to stand in line at their local war memorial as they have done for so many years.

Others, like the remarkable Henry Allingham, who at 109 is the country's oldest man, will appear steadfast at the Cenotaph in Whitehall to remember the fallen on Remembrance Sunday.

It is believed only nine First World War veterans survive, including Mr Allingham who lives in Eastbourne and served with the Royal Naval Air Service (RNAS) and Harry Newcombe, 105, from Worthing , who was a soldier with the Sussex Regiment.

On Friday and again on Sunday, they will each pay their respects to friends who died in a war which ended 87 years ago.

Dennis Goodwin, chairman of the World War One Veterans' Association, said: "We all tend to forget that the ravages of time are well and truly advanced in these men.

"Yet despite those ravages, there will still be a great sense of pride and sorrow among their number and they will mark the day, make no mistake."

Mr Allingham, who served as an air mechanic and fought at the third battle of Ypres and the Somme, will fly to the former British air base of St Omer in France on Armistice Day to lay a wreath at a memorial for all the airmen who lost their lives during the conflict.

On Sunday he will join the Fleet Air Arm Association at the Cenotaph.

Mr Goodwin said it was right future generations should continue to mark the occasion.

He said: "I thought the soldiers were supermen.

"I admired them for what they did on our behalf.

"If it wasn't for them our whole history could have been very different."

Mr Allingham volunteered in 1914, when he was 18. He was sent to the Western Front, carrying out repairs to legendary planes like the Sopwith Camel.

He is the last survivor of the Battle of Jutland and the last surviving founder member of the Royal Air Force when the RNAS and Royal Flying Corps merged in 1918.

Despite being shot in the arm while in the trenches at Ypres, Mr Allingham fought throughout the war and joined car maker Ford when it finished.

His engineering expertise was later used to counter German magnetic mines in the Second World War.

His wife of 53 years, Dorothy, and their two daughters have since died but Mr Allingham has five grandchildren and 12 great-grandchildren who live in America.

In 2003, he was awarded France's highest military honour, the Legion d'Honneur.

Meanwhile Mr Newcombe, who passed through France and into Germany as part of the army of occupation at the end of the Great War, will pay his respects from his bed after suffering a stroke. He joined the Army on his 18th birthday and when he left in 1919, he worked on the railways.

He never married and joined the RAF in the Second World War but did not serve overseas.