Prince Charles risks diplomatic row over Chelsea Barracks

He wants the Emir of Qatar to scrap a modernist glass-and-steel development designed by Lord Rogers and has drafted a more traditional plan for the site - prompting accusations that he was bypassing the planning process.

Charles also risks causing a wider controversy over Britain's energy sources because Qatar is set to provide the UK with more than 20 per cent of its gas needs. Under government plans to reduce the country's dependence on oil, Qatar has built the world's biggest liquefied natural gas terminal in South Wales. The Queen is set to formally open the terminal alongside the Emir of Qatar next month.

The Chelsea Barracks row centres on flats planned for the site opposite the Royal Hospital. Although opposed by some residents' groups, the scheme meets planners' demands for affordable housing and wider planning guidelines. If it fails to win permission from Westminster City council, there are fears the project will be mothballed, the site blighted for years and thousands of jobs lost. It emerged yesterday that Prince Charles has urged the project's owner, Qatari Diar, the development arm of the Qatari royal family, to drop Lord Rogers.

Charles has branded the scheme, previously headed by developers Nick and Christian Candy, "unsympathetic" and "unsuitable" for the area.

The Prince has written to the prime minister of Qatar urging him to adopt a classical scheme, revealed in the Standard for the first time, by one of his favourite architects, Quinlan Terry. Charles has asked to be kept involved in talks over the future of the site.

The move echoes the Prince's "carbuncle" speech made 25 years ago in which he heavily criticised plans for an extension to the National Gallery.

Prince Charles wants a classical design, made from bricks, stone and slate, which mirrors Sir Christopher Wren's Royal Hospital across the road.

Today, a source close to the Lord Rogers' scheme said: "Prince Charles's renewed attack on modernist architecture amounts to unfair privileged intervention by a prince who does not want to engage in public debate apart from interfering behind the scenes. This is unfair and skews democratic process of planning for public spaces."

"The Prince is happy to pronounce his views from the sanctity of his palace but not to enter into any proper debate. By saying that all buildings must have doric or ionic columns is like dictating that all newspapers can only use a sans serif typeface and not have the viability and excitement of change and progress.

"If it was not so consequential to how our country looks it would be comic, like forcing everyone today to wear togas. The scary thing is that he can influence the way our country looks and prevent architects from getting work and all by his status and not through any accountable ways of responsible decision-making. We should not be in an era of the divine right of kings or princes."

The Prince's intervention emerged at the opening of the Royal Hospital's Infirmary on 25 March, attended by Lady Thatcher, the Prince and Mr Terry, who designed the classical addition to Wren's masterpiece.

Mr Terry revealed: "He told us all how unhappy he was with the current proposals. He made it clear to all of us that he was even more determined to battle over this site to protect and enhance this important corner of London."

Qatari Diar today said they had not been surprised by the Prince's views.

A spokesman for the Qataris said: "We have always been aware of HRH the Prince of Wales's public views on modern architecture and we have been expecting that he would favour a more traditional approach. Whilst our submitted scheme is modern, we share HRH's views on integrated sustainable developments and we are currently in dialogue with his representatives."

Ken Livingstone today urged Boris Johnson to speak out to defend Lord Rogers. He said: "If world-class architects think they or their designs are going to be the subject of pressure by the heir to the British throne there is a danger we will lose the ability to attract them at all - which would be a recipe for excessive caution and mediocrity." Lord Rogers was abroad and unavailable for comment. The Candy brothers declined to comment.