Diana always in my thoughts, says Prince Harry

The 25-year-old royal said that conjuring up her memory no matter where he is or what he is doing keeps himself and brother Prince William, 28, "going every day". Harry joked that one word he would use to describe his mother would be "mad".

The Prince's comments came in a TV interview given during a recent tour of southern Africa with his older brother which ended on the weekend.

The Princes visited their charitable interests while away, with William taking his younger sibling to see a range of projects supported in Botswana by the conservation organisation Tusk Trust which the 28-year-old supports as royal patron. Harry showed his older brother the work of his body Sentebale in Lesotho, which helps disadvantaged children.

Asked what his mother would have thought of their charity work in Africa, Harry replied: "Every day, I know I do and I'm sure William does as well, whatever we do, wherever we are and whoever we're with I particularly always wonder what she'd think, what she'd be doing if she was with us now.

"If she'd be sitting here having a laugh, whether she'd be in the background sticking her tongue out or whether she'd be playing football with the children. That's what keeps us going every day – that thought of what would she be like if she was around today. It's refreshing because we both have our own opinion of what she'd be like and mad would be one word to describe her."

Earlier this week Harry evoked memories of his mother when he visited a charity clearing minefields in Africa just as Diana had done in the late 1990s and was pictured wearing similar body armour and face mask as the Princess during her trip.

William and Harry - the Brother Princes: Tonight will be screened on ITV1 tonight at 7.30pm.