Mohamed al Fayed, never one to back away from a public confrontation, has accused John Prescott of "unlawfully and irrationally" preventing him from landing his helicopter on the roof of Harrods.
The multimillionaire began a High Court attempt yesterday to overturn the former environment secretary's refusal to allow construction of a helipad on the building in Knightsbridge, London.
Mr Prescott personally rejected the scheme in January, overturning a planning inspector's decision. Yesterday Guy Roots QC, appearing for Harrods Ltd, told Mr Justice Sullivan: "In short, we say the inspector was right and the Secretary of State was wrong."
Mr Fayed had appealed against a refusal by the Royal Borough of Kensington and Chelsea to grant him a "lawful development" certificate to land helicopters on the roof of his store.
There was a public inquiry in July last year, and the planning inspector ruled in favour of Mr Fayed on the basis that the use of a helicopter was "ordinarily incidental" to his daily routine as Harrods chairman.
There was no reason Mr Fayed should not be permitted to land his helicopter on the roof up to 10 times a week, the inspector said.
But Mr Prescott then intervened, overturning the inspector's decision and siding with Kensington and Chelsea. He decided the use of the helipad was much more related "to the needs and requirements of the store owner than to the main retail purpose of the store". The helipad would not "support or facilitate" that use and was not "ordinarily incidental" to it.
Yesterday Mr Roots argued that Mr Prescott had adopted the wrong test and was guilty of a number of errors of law.
He had taken account of irrelevant considerations, in breach of planning rules and regulations, and reached "irrational" conclusions without the evidence to support them, he told the court.
The case continues.