When officials from the Royal Norfolk Agricultural Association were organising the ground-breaking ceremony to launch the construction of its £3m Food Hall project they thought they had the perfect tool for it.

They planned to use a spade wielded by the late Queen Mother when she planted a tree on a visit to the Royal Norfolk Show in 1952 and kept in a special display case ever since.

But in the end, showground bosses considered the 72-year-old royal relic simply too treasured to be used and handed the guest of honour Lady Philippa Dannatt, the Lord Lieutenant of Norfolk, another gardening tool instead.

Mark Nicholas, RNAA managing director, said: "The spade last used by the Queen Mother in 1952 was too precious to be used today, so we decided to put it into our heritage collection, and it has been succeeded by the Dannatt spade."

The Queen Mother planting a tree at the 1952 Royal Norfolk ShowThe Queen Mother planting a tree at the 1952 Royal Norfolk Show (Image: RNAA) Using the new tool, Lady Dannatt, the King's official representative in the county, launched the Norfolk Food Hall project, saying it was an "exciting day for Norfolk", and its agricultural industry - regardless of the digging implement used.

The Queen Mother's spade, in its cabinet at the Norfolk ShowgroundThe Queen Mother's spade, in its cabinet at the Norfolk Showground (Image: RNAA) "I think this is one of the most important and most exciting developments that I have seen since I became Lord Lieutenant," she added.

"It is a fabulous day for Norfolk, and for Norfolk farming in particular, which is what Norfolk really stands for.

"We are an agricultural county so, for that reason along with many others, the fact that this food hall is going to showcase and serve our farming community so superbly well - I feel very proud of that."

Lady Dannatt, Lord Lieutenant of Norfolk, breaking the ground in a ceremony to mark the building of the Norfolk Food Hall at the Norfolk ShowgroundLady Dannatt, Lord Lieutenant of Norfolk, breaking the ground in a ceremony to mark the building of the Norfolk Food Hall at the Norfolk Showground (Image: Denise Bradley) Around 200 guests, including VIPs, political leaders and business supporters, gathered for the traditional ceremony at the Norfolk Showground.

Construction work has already begun on the Norfolk Food Hall, described as a "flagship showcase" for the county's agri-food sector - creating 25 new jobs and a valuable shop window for food and drink producers.

RNAA commercial director Richard Greenacre said "the first major development on this site for 40 years" has been supported by 45 businesses which have contributed to the costs.

Plans also include a 140-seat restaurant, butcher, delicatessen and outdoor seating area, located near the site's main entrance gate.

Construction work has begun on the Norfolk Food Hall building at the Norfolk ShowgroundConstruction work has begun on the Norfolk Food Hall building at the Norfolk Showground (Image: Denise Bradley) Lady Dannatt, Lord Lieutenant of Norfolk, breaking the ground in a ceremony to mark the building of the Norfolk Food Hall at the Norfolk ShowgroundLady Dannatt, Lord Lieutenant of Norfolk, breaking the ground in a ceremony to mark the building of the Norfolk Food Hall at the Norfolk Showground (Image: Denise Bradley)