Portland MP Ian Bruce says he is "absolutely adamant" that Geoff Smith of stone specialists Easton Masonry will not be made a scapegoat for the use of French limestone to build the South Portico of the British Museum's Great Court Scheme.

The masons, based on the Dorset island of Portland, supplied what was specified, says Bruce.

In a letter to Suzanna Taverne, managing director of the British Museum, dated 4 September, Ian Bruce writes: "You will know I have correspondence from you and the architects asserting that the French stone was to specification and that you were perfectly happy to proceed despite being told two years ago that French stone and not Portland stone was being used, firstly denying that that was the case and then secondly saying it was to specification anyway".

"Now that the local planning authority has joined in the protests that were made by myself, you appear to be looking for a scapegoat".

"May I suggest that firstly you pay Easton Masonry for the stone that has been supplied to you according to your specification, you then get your architects to pay for the demolition and rebuilding of the portico in Portland stone and after you have done that, you resign."

Copies of the letter were also sent to Lord Foster, whose architectural practice, Foster & Partners, led the project, and Chris Smith, the Secretary of State for Culture, Media & Sport, who instigated an investigation into the affair after it came to light last year (see NSS November 1999).

A draft of a report, carried out for the British Museum by London accountants PricewaterhouseCooper, has now been presented to the Museum, although its contents remained secret at the time of going to press.

The portico, meanwhile, was being given a high pressure wash at the recomendation of the architects in the hope that removing any residual stone dust on the structure might tone it down.

In a statement on 22 September the British Museum said Easton Masonry had "perpetrated a deceit as to the source of the stone supplied and in July last year Fosters had recommended that the stone should be replaced".

The Museum Trustees decided that the South Portico was an entirely new construction and the stone and construction were appropriate and of high quality.

They, with the subsequent support of Fosters and with the agreement of English Heritage, according to the Museum statement, decided the work should be completed in the French stone.

The Museum statement concludes: "Once the washing is complete, the South Portico will be reviewed to see to see whether any other action is necessary.

"The British Museum is confident that the portico will then come to be seen as a splendid and appropriate part of the Great Court, one of the millennium's most exciting and significant projects."

Nevertheless, the Museum has refused to pay the final £250,000 instalment for the work to Easton Masonry, even though that work was completed, according to Ian Bruce, to specification and on time.

"It seems to me," says Ian Bruce in a letter to Michael Poultney, Managing Director of Portland stone quarriers Albion Stone, "that the 'establishment' is trying to wriggle out of its own responsibilities and I am adamant that the same people who rebuffed you and me will not be allowed to get away with it."

He says that in their wriggling, those authorities have already exonerated Easton Masonry and "I feel honour-bound as the local Member of Parliament to protect them from the backlash of this".