Number 10 invitation for forces families

The event was in aid of Tickets for Troops, of which the Prime Minister's wife became a patron after David Cameron helped launch it last year.

The charity obtains free tickets for military personnel to attend major sporting and music events.

The event happened as comrades of a Yorkshire trooper killed in an explosion in Afghanistan paid tribute to the "model soldier".

James Leverett, 20, who grew up in Sheffield and Rotherham and attended Rawmarsh Comprehensive School, was in a vehicle which struck an improvised explosive device on Monday in Helmand Province.

He was also described as an "adoring" boyfriend who was looking forward to the birth of his first child.

The commanding officer of the Royal Dragoon Guards, Lt Col James Carr-Smith, said: "Trooper James Leverett, known as Levy, was a Royal Dragoon Guard of significant potential. He had only been with the regiment for 18 months but in this short time he had more than made his mark. He was a model soldier."

His family said: "James was strong-minded and determined. Whatever he set his mind to, he kept on trying until he achieved his goal."