Camilla, the Duchess of Cornwall, is to visit Marlborough next week to help put the seal on the town’s commemorations of the Queen’s Diamond Jubilee, it was revealed yesterday.

The Duchess will unveil a mural made by the Marlborough Tile Factory showing scenes of the town on Friday.

For protocol reasons the royal visit had to be kept under wraps until yesterday, said mayor Edwina Fogg.

“We have been negotiating behind the scenes for months to get a royal visitor to come to unveil the mural and we are delighted that the Duchess has accepted the invitation,” she said.

On arriving at the town hall on Friday morning the Duchess will be met by Coun Fogg.

After being presented with a posy of flowers by a pupil from St Peter’s School she will be taken by the mayor to see the old cells in the basement where criminals were kept when the hall was used for the Assizes and Quarter Sessions courts.

Coun Fogg will then lead the Duchess up wooden steps from the cells and through a trapdoor into the courtroom where judges meted out justice until 70 years ago.

Waiting in the courtroom will be guests who have helped Coun Fogg with organising the Jubilee celebrations and members of organisations including St Peter’s School and St Mary’s Church that are represented on the huge mural.

Coun Fogg said: “For me this will be absolutely the high point of the Jubilee year and the celebrations in Marlborough.”

She said in her acceptance speech at the mayor-making ceremony in May that she would like to see a mural of the town as a permanent feature of the Jubilee celebrations.

Marlborough Tiles took up the challenge.

Four of the Elcot Lane company’s highly skilled artists have spent weeks hand-painting the tile mural that features the High Street and its iconic buildings together with features from the surrounding area including Savernake Forest, Silbury Hill and Wilton Windmill.

Having seen the mural –which is topped with a hand-painted coat of arms – in its final stages, Coun Fogg said: “It is beautifully done; I can’t tell you how lovely it is.

“I am sure that when people see it they will agree that it is a stunning piece of work and we cannot thank enough Marlborough Tiles and their MD Jamie Robb for doing this for the town.”

The four artists from Marlborough Tiles will be presented to her.

The mural will later be hung permanently in the court room, where there is a plaque recording that the Prince of Wales visited Marlborough during its 800th charter anniversary celebrations in 2004.

Although the Duchess, then Camilla Parker Bowles, came to the town the same day, a year before their marriage, she was not part of the official royal visit.