The new but traditionally built stone tower at Bury St Edmunds cathedral, which is due to be finished next year, has been praised by Prince Charles after attracting criticism over its £10.3million cost and its Gothic design.

Prince Charles has reportedly described the tower, which has received £5million funding from the Lottery, as "a spiritual beacon for the future".

The project to turn the church into a cathedral was begun in 1958, after the creation of the diocese of Edmundsbury & Ipswich in 1943. By 1970 it had run out of steam and money and the work was not resumed until 2000, when the Heritage Lottery Fund had made its contribution.

The tower is being built in the traditional way by stone specialist Andre Vrona of Ketton Stone, who has an established reputation for building exclusively in solid stone.

About 1,500 tonnes of Ketton freestone from Castle Cement's Ketton Quarry in Rutland are being used in the same way that they would have been used by medieval masons, including the use of lime mortar.

Ketton Freestone was chosen at the suggestion of Andre Vrona. "It's a very reliable and powerful stone; a good load-bearing masonry for both internal and external use," he says.

"The designers were looking at another stone originally, but then I looked at an artist's impression, which captured light coming through the window and a lovely golden stone. It was then that I suggested freestone from Ketton.

"It is good for load bearing because it allows movement. It allows flexing, bowing and bending and recovers itself. This is a traditional build concept. The stone acts in a manner that traditional buildings do. The load bearing masonry locks together."

When building work on the 16th century church in Bury St.Edmunds is completed next year it is expected to last "for at least 1,000 years", according to project co-ordinator Euan Allen from Suffolk Cathedral Millennium Project.

Hory Parsons, team leader for main contractor Bluestone plc, agrees that the Ketton stone "is giving an excellent quality finish to the interior of the tower."

The use of lime mortars with the stone has involved the re-inventing of mixes, including the addition of a dash of linseed oil for the damp-proof course.

Work on the project re-started in 2000 (see the first report on the project in NSS, January 2000). When it is finished it will be the first - and possibly even the last - Gothic building in the UK in the 21^st century.