Prince Charles wrote directly to the chairman of Qatari Diar
Prince Charles has come under attack from the architectural community for effectively blocking a building project at Chelsea Barracks in west London.
A former planning minister said the prince had set a "very dangerous precedent" by using his contacts with the Qatari Royal Family to intervene.
The firm Qatari Diar commissioned architect Lord Rogers to design the £3bn flats near the River Thames.
The Middle Eastern owners withdrew their planning application on Friday.
The decision followed a direct intervention by the prince, who wrote to the chairman of Qatari Diar, urging him to consider alternatives to the modern design created by Lord Rogers's firm of architects.
It is believed the prince wanted a more classical, traditional scheme.
Labour MP Nick Raynsford said Prince Charles' behaviour had been "almost feudal".
"I do believe there is a very dangerous precedent here when the heir to the throne intervenes in a decision which should be taken through normal democratic processes, " he told the BBC Radio 4's Today programme.
"There is a very real constitutional issue when the heir to the throne becomes engaged in political controversy cutting across the normal democratic processes by which planning decisions should be taken in this country," he added.
Qatari Diar hope to submit a new planning application this year
Mr Raynsford has been backed by the President of the Royal Institute of British Architects, Sunand Prasad, who said the Prince's intervention could deter investors from developing projects in London.
"It is not a good day for confidence in the British way of doing things," he told Today.
Lord Rogers, who has designed some of the most influential buildings in the world, said it was a "disastrous" decision.
He said the project had already undergone two and a half years of consultation with local authorities and residents.
The real estate investment company Qatari Diar is owned by the Qatari Investment Authority, which is headed by the country's prime minister.
The Chelsea Barracks site was sold by the Ministry of Defence to Project Blue (Guernsey) Limited (PBGL) for £959 million in January 2008. PBGL is owned by Qatari Diar.
A spokesman for PBGL said it was working with a range of stakeholders - including the Prince's Foundation for the Built Environment - to find a new design.
But Mr Prasad warned that the redesign process could result in a "pastiche".
"We are really throwing in the towel if we think in the 21st Century that we can't make beautiful buildings that can face a site of magnificent buildings across the road, he said.
"They can be beautiful without being neo-classical."
Mr Raynsford said he was concerned the redesign would result in "an unsatisfactory outcome on the Chelsea Barracks site".