Prince Philip has his 51-year-old trousers unpicked and restyled into the latest fashion

Prince Philip has asked his Savile Row tailor to change a particularly favourite pair from the baggy style that was popular in the Fifties into something more contemporary.

The thrifty 87-year-old had the trousers produced as part of a bespoke suit in 1957. But now he wants them to chime with 21st Century tastes and has instructed John Kent – his personal cutter at tailors Norton & Sons – to straighten the legs.

Thrifty Philip ... taking the credit crunch in his strides

Patrick Grant, one of the directors of the firm whose suits were worn by Lord Mountbatten and a young Winston Churchill, said the Prince wanted a ‘snappier’ look. ‘John has been making the Prince’s clothes for many years and has a Royal warrant,’ said Mr Grant.

‘About six weeks ago, the Prince sent him a pair of trousers that he wanted recutting to give a slimmer, more fashionable look.’

The original suit was made of a heavyweight worsted cloth, with a distinctive grey and brown herringbone stripe. Mr Grant said the seams had now been unpicked and resewn to narrow the legs.

Mr Grant added: ‘The Prince likes substantial cloth. He certainly gets plenty of wear out of all his clothes.’

Friends of Prince Philip said it was not unusual for him to keep favourite items of clothing for decades, repairing or altering them when necessary.

At naval events he is often seen in the same uniform that he wore at his wedding on November 20, 1947.

One friend said: ‘He is part of the thrifty wartime generation that never wastes anything. If he likes something, he doesn’t see the need to throw it away.

‘As he gets on for 90, he is still well dressed and up with the trends. But maybe family members have been ragging him about his baggy trousers and he has finally decided to get them changed.’

He added: ‘One of the most remarkable things is how he has managed to maintain his waist size when most of us have seen it expand.’

Although it is long after his days as a youthful and debonair naval officer, the Prince is still praised by fashion experts for his impeccable taste. In the latest list of the best-dressed men in Britain, compiled earlier this year by GQ magazine, he appeared at number 33, beating the likes of Hugh Grant.

Buckingham Palace declined to comment, saying it was a personal matter for the Prince.